IE6 Flicker worse now than ever???

boyersmile · February 28, 2006

I'll try to explain this as best I can, but I'm sure there might be additional questions. I know that this isn't a problem with my customization because I've tested this with standard uncustomized smugmug sites. I know the problem with the IE flicker was supposedly last week. It seems to me that the problem is even worse now.

It used to be that I would experience this IE flicker only if I opened one of my gallery pages, left it open for about an hour, came back and hovered over the thumbnails. Under these circumstances, the thumbnails would "flicker" while the thumbnail refreshed. At the same time, the little "windows flag" would wave showing that the page was still loading. Is this what everyone was calling the IE flicker?

The problem seems to be worse now. I've noticed that starting the day of the last fix, any image in my cache would flicker. This would happen any time I loaded a gallery that I had previously visited. Ok- simple fix- clear my cache. Well that works, but only for a day (give or take on the time. I haven't thoroughly tested that). The first time this happened, I cleared my cache and thought I had it fixed. Unfortunately, the same thing happened the next day. This has happened on 3 seperate computers, all running IE6. I've had to clear the cache each day in order to keep the thumbnails from flickering. I've tried a couple different options in the cache settings for IE, but I would think the site should operate properly regardless of the cache settings.

I can pretty safely say that the only images that flicker are images that were previously stored in my cache. For instance, the second page of one of my galleries doesn't flicker today, but the first page does. Yesterday, I did view the first page of the gallery, but not the second page. In addition to the thumbnails, this happens with the larger images in the "smugmug" style. For someone using a dialup connection, they might look at an empty picture for several seconds any time they hover over a picture. This seems to happen in all of my galleries.

Has anyone else experienced such a thing. I've seen several other posts lately with various problems relating to the cache. While it was understandable to clear the cache once after the recent changes and recent "attacks", I don't think this is how it is supposed to work. I don't expect my viewers to clear their cache all the time.

Here is a screenshot that shows what happens when I quickly hover over all the images in a gallery. (I was uploading at the time, so my connection was slow enough to give me time to get a screen capture while several of the thumbnails were still blacked-out.) This page had completely loaded and all images were showing until I hovered over them.

This is the gallery I was viewing: http://www.boyersmile.smugmug.com/gallery/355422

Let me know if you have any more questions. I probably won't check back until tomorrow morning. I hope someone else is able to recreate this problem.

Thanks,
Miles Boyer

flyingdutchie · February 28, 2006

No problem here.
I use IE6 on Windows XP (service pack 2).
Note that you have to set your settings as in this screenshot:
(Note the 'automatically' setting of caching.)

If i set it to 'every visit', i get a lot of flickering.

boyersmile · February 28, 2006

flyingdutchie wrote:

No problem here.
I use IE6 on Windows XP (service pack 2).
Note that you have to set your settings as in this screenshot:
(Note the 'automatically' setting of caching.)
If i set it to 'every visit', i get a lot of flickering.

I usually do keep it set at "automatically", although I have changed it around while trying to determine the problem. I'll have to check the other computers tomorrow, but I'm pretty sure they are set the same way. I still wouldn't expect my users to need to change this setting.

Even if they have it set to "every visit", the images should be the same. Even if it downloads a new copy of the image when it first loads the page, I wouldn't think that it would keep checking each time you hover over an image. The page doesn't chage when you hover over an image does it?

The fact that I see this on three seperate computers and while viewing different smugmug sites makes me think that I'm not the only person seeing this problem. I'll do some more testing to see if I can more accurately describe when it does and doesn't happen. Unfortunately, it seems to take about 1 day after clearing the cache before the problem shows up again.

Thanks,
Miles

{JT} · February 28, 2006

boyersmile wrote:

Even if they have it set to "every visit", the images should be the same. Even if it downloads a new copy of the image when it first loads the page, I wouldn't think that it would keep checking each time you hover over an image. The page doesn't chage when you hover over an image does it?

According to IE it does if the image is a background image

The fixes we made though should over ride any settings you have and not flash though. I will take a look to see why you might see this problem.

Andy · February 28, 2006

I'm poking around your site in IE6 and I see no flicker...

boyersmile · March 1, 2006

Andy and JT- Thanks for looking into this.

Andy- you probably won't notice any flicker the first time you visit my site, but if you come back the next day and visit the same galleries you will. At least that is what is happening with me. That is what makes this difficult to test. You have to wait a day to see the problem.

I would also like to reiterate that this shouldn't have anything to do with any customizations on my site. I've noticed the problem on other standard smugmug sites that I visit regularly.

I'll try to do some more investigating today.

Thanks,
Miles

Andy · March 1, 2006

boyersmile wrote:

Andy and JT- Thanks for looking into this.

Andy- you probably won't notice any flicker the first time you visit my site, but if you come back the next day and visit the same galleries you will. Miles

went back, no problems... no flicker. Sorry Miles I can't reproduce.

boyersmile · March 1, 2006

I will definitely have to do some more testing. I'm now using my computer at work. IE6 is set to use the "automatically" cache setting. I do remember clearing the cache 2 days ago on this computer.

When I view my photo of the day gallery through this address:
http://www.boyersmile.smugmug.com/gallery/355422
all of the thumbnails flicker EXCEPT for the first two, which have been added to the gallery since I cleared the cache.

When I view my photo of the day gallery through this address:
http://www.milesboyer.com/gallery/355422
none of the thumbnails flicker.

I am getting different results when viewing the gallery through my custom domain vs the smugmug domain. I can't remember the various combinations of settings, domain name, and computers that I've checked this out on, but I am definitely seeing different results between the domain names.

I am also wondering if this has something to do with the fact that this gallery is updated daily. I'm not sure how IE determines whether or not to download a new thumbnail. Does it just look at the actual image name, or does it check its placement on the page? The reason I ask is because the gallery page does change each day, since I add a new photo to the beginning of the gallery. I haven't been able to narrow down the exact pattern, but I can pretty safely say that if I clear the cache today; then add a photo to the gallery for the next 2 days; then check back in 3 days; all the thumbnails will flicker except for the new images that have been added since I cleared the cache. (wow, I hope that run on sentence makes more sense to someone else)

One of the other sites that I've seen these same results with is www.ricardo38.smugmug.com. He also has a photo of the day gallery. I can't reproduce the problem right now (possibly because I haven't visited his site from this computer in the past few days), but in the past few days I have noticed the exact same problems I'm seeing on my site. I promise I'm not making this stuff up.

With all the variables that are involved, plus the fact that it seems to take at least a day to test this issue, this is a bit difficult to troubleshoot. I will continue to try to narrow down this problem, so that it can be reproduced.

Andy- when you checked my site, which domain did you use? You might want to try both. Then check back tomorrow when I add a new picture.

Thanks for any and all help. If someone else is able to reproduce this problem, please let me know. Really, it is happening. I promise. I'm not crazy. Well- Ok, I am. But not crazy enough to imagine this.

Thanks,
Miles

Andy · March 1, 2006

boyersmile wrote:

Andy- when you checked my site, which domain did you use? You might want to try both. Then check back tomorrow when I add a new picture.

No flickery with either domain...

boyersmile · March 1, 2006

Thanks Andy, I'll keep checking into it.

I'm really not crazy. I probably wouldn't worry about this if did just happen from 1 computer, but it happens from 3 different computers that I use. Maybe I'm just cursed.

Thanks,
Miles

boyersmile · March 2, 2006

Andy-
If you haven't cleared your cache in the last few days, would you mind checking my site again. Check the same gallery you checked the other day. If you aren't seeing the problem, I wonder if it has something to do with you using a Mac.

I did clear the cache on 3 separate computers on February 28th. I have viewed the same gallery from each computer each day since then. I didn't see the problem on the March 1st. I do see the problem from all three computers today (March 2nd). The only photo that doesn't flicker is the first photo in the gallery. So it looks like it takes maybe at least 36 hours after initially viewing the gallery before the photos start to flicker.

I haven't had time to do a thorough scientific test yet, but I will continue to investigate.

If anyone else (maybe another XP IE6 user) wants to help in the investigation, please check this gallery today

http://www.milesboyer.com/gallery/355422

Then check back in about 3 days. Let me know if the thumbnails flicker.

Thanks,
Miles

{JT} · March 2, 2006

There is no need to wait 3 days, just set your system clock ahead a week and check. I just did, and yes I see the flicker. But, as I have said in a lot of other threads here, this bug will be next to impossible to solve 100% of the time. IE sucks at caching background images, since you have protection on, there are background images everywhere. I can talk to Don about bumping up the expiration date for the image - but I don't think we will change it since that creates different problems for us.

boyersmile wrote:

Andy-
If you haven't cleared your cache in the last few days, would you mind checking my site again. Check the same gallery you checked the other day. If you aren't seeing the problem, I wonder if it has something to do with you using a Mac.

I did clear the cache on 3 separate computers on February 28th. I have viewed the same gallery from each computer each day since then. I didn't see the problem on the March 1st. I do see the problem from all three computers today (March 2nd). The only photo that doesn't flicker is the first photo in the gallery. So it looks like it takes maybe at least 36 hours after initially viewing the gallery before the photos start to flicker.

I haven't had time to do a thorough scientific test yet, but I will continue to investigate.

If anyone else (maybe another XP IE6 user) wants to help in the investigation, please check this gallery today

http://www.milesboyer.com/gallery/355422

Then check back in about 3 days. Let me know if the thumbnails flicker.

Thanks,
Miles

boyersmile · March 2, 2006

{JT} wrote:

IE sucks at caching background images, since you have protection on, there are background images everywhere.

I'm so glad that I'm not the only one seeing this problem.

See, I'm really not crazy. So if I turn off the image protection, will this problem go away? That might be something I would consider, but I would like to know if anything else can be done. Maybe I'll just have to convince everyone to use Firefox.

Thank you for looking into this JT.

Miles

flyingdutchie · March 2, 2006

boyersmile wrote:

I'm so glad that I'm not the only one seeing this problem. See, I'm really not crazy. So if I turn off the image protection, will this problem go away? That might be something I would consider, but I would like to know if anything else can be done. Maybe I'll just have to convince everyone to use Firefox.

Thank you for looking into this JT.

Miles

Don't worry, or better, everyone worry!

I have the same thing happening to my site.
It does not happen always. It just happens sometimes.

Use IE6.0
1. Go to a gallery with protected images.
...
... day(s) later ...
2. Go to a gallery with protected images again.
3. Everytime you mouse over an image, the image 'flickers'.
4. Even my site's background image (image background on every page) flickers when i move from page to page.
5. This keeps happening until i remove all cached files (Tools --> Internet Options... --> Delete Files).
6. After i do that, all is fine again... until.... Start again at point (2.)

I guess we have to live with that

or not 'protect' your images.

{JT} · March 2, 2006

Yeah, we are looking at some other work arounds. But in the end, IE is broken. You can set your cache to automatic though and that will fix it.

flyingdutchie wrote:

Don't worry, or better, everyone worry!
I have the same thing happening to my site.
It does not happen always. It just happens sometimes.

Use IE6.0
1. Go to a gallery with protected images.
...
... day(s) later ...
2. Go to a gallery with protected images again.
3. Everytime you mouse over an image, the image 'flickers'.
4. Even my site's background image (image background on every page) flickers when i move from page to page.
5. This keeps happening until i remove all cached files (Tools --> Internet Options... --> Delete Files).
6. After i do that, all is fine again... until.... Start again at point (2.)

I guess we have to live with that or not 'protect' your images.

flyingdutchie · March 2, 2006

{JT} wrote:

Yeah, we are looking at some other work arounds. But in the end, IE is broken. You can set your cache to automatic though and that will fix it.

My cache was and is set to automatic... and Miles and I (and maybe more people) have this problem.

If i set the value to 'every visit to the page', i get the flicker every time when i move my mouse over the picture all the time, no exception (no need to wait for day or so).

If i set it to 'automatic', i get it every other day or so. Clearing the cache will fix it, though, and moving the mouse will no longer make the images flicker.

And the flicker is not only in the images, it's even in my main background image (the sand-pattern) when i move from page to page.

I know it's a nasty IE6 bug, but the setting 'automatic' used to be good enough. After the latest smugmug release, the flicker starts again every other day until i clear the cache. Something in the cache-protocol changed....

flyingdutchie · March 2, 2006

{JT} wrote:

Yeah, we are looking at some other work arounds. But in the end, IE is broken. You can set your cache to automatic though and that will fix it.

What if, for images, no 'Expires' header is sent, but only a 'Last-Modified' response-header?

flyingdutchie · March 5, 2006

Only thumbnails flicker.

{JT} wrote:

Yeah, we are looking at some other work arounds. But in the end, IE is broken. You can set your cache to automatic though and that will fix it.

Strange... this 'new' flicker only seems to happen with thumbnails.... E.g. in Smugmug or Smugmug_small style galleries, the main picture never flickers. The thumbnails (also in all_thumbnails style gallery) do flicker.

boyersmile · March 6, 2006

flyingdutchie wrote:

Strange... this 'new' flicker only seems to happen with thumbnails.... E.g. in Smugmug or Smugmug_small style galleries, the main picture never flickers. The thumbnails (also in all_thumbnails style gallery) do flicker.

I am having problems with the main picture flickering in smugmug and smugmug small galleries. It only happens on pictures that I have actually viewed, but it definitely is happening for me with the larger size pictures. In fact, I noticed last night that it happened with a few single image with comment photos too.

I am probably more worried about these larger images flickering because a viewer on dialup might be looking at a black box for several seconds each time they hover over an image. This could be very frustrating for dialup users.

JT- I also have my IE cache set to "automatically", but I still have this problem. I have this same setting on at least 3 different computers, and they all show this flicker.

Just thought I would clarify a few points in case it helps to find a solution.

Thanks,
Miles

onethumb · March 6, 2006

flyingdutchie wrote:

What if, for images, no 'Expires' header is sent, but only a 'Last-Modified' response-header?

That's what we've done since the beginning of time. (Well, ok, since the beginning of smugmug

Alas, IE is broken and dumb with this issue.

We made some more changes today. Any improvement?

Don

flyingdutchie · March 6, 2006

onethumb wrote:

That's what we've done since the beginning of time. (Well, ok, since the beginning of smugmug

Alas, IE is broken and dumb with this issue.

We made some more changes today. Any improvement?

Don

Thanks!

I will test it tomorrow again and see if a flicker occurs.
But about the 'Expires' header: Smugmug still sends out an 'Expires' http-header. I get this result with graburl:

C:\>graburl -h http://flyingdutchie.smugmug.com/photos/45469061-Th.jpg
HTTP/1.1 200 OK
Date: Tue, 07 Mar 2006 04:35:00 GMT
Server: Apache
ETag: sm-096a4be4bae235a515819d20a2f9bb2e-sm
X-Powered-By: smugmug/1.1.0
Last-Modified: Sat, 28 Jan 2006 04:16:35 GMT
[B]Expires: Thu, 06 Apr 2006 04:35:00 GMT[/B]
Cache-Control: public
Content-Length: 7604
X-Extra: 0.043215990066528
Connection: close
Content-Type: image/jpeg

Based on the 'Expires' header from above, the flicker will not be seen until April 6th. But, after this date, the flicker will happen again. What if the 'Expires' header is not sent at all and only the 'Last-Modified' header will be used? Would IE6 like that?

onethumb · March 7, 2006

flyingdutchie wrote:

Based on the 'Expires' header from above, the flicker will not be seen until April 6th. But, after this date, the flicker will happen again. What if the 'Expires' header is not sent at all and only the 'Last-Modified' header will be used? Would IE6 like that?

No, that was the point of my previous post. The 'Expires' header is new to smugmug. We were doing Last-Modified forever, and lots of complaints about flickering.

IE6 hates non-expired background images, apparently.

Assuming no-one is seeing flickers between now and April 6th, I'll likely crank it up to be 10 years or something. That oughta learn that pesky browser.

Don

flyingdutchie · March 7, 2006

onethumb wrote:

No, that was the point of my previous post. The 'Expires' header is new to smugmug. We were doing Last-Modified forever, and lots of complaints about flickering.

IE6 hates non-expired background images, apparently.

Assuming no-one is seeing flickers between now and April 6th, I'll likely crank it up to be 10 years or something. That oughta learn that pesky browser.

Don

Go get'm, Don!

onethumb · March 8, 2006

onethumb wrote:

No, that was the point of my previous post. The 'Expires' header is new to smugmug. We were doing Last-Modified forever, and lots of complaints about flickering.

IE6 hates non-expired background images, apparently.

Assuming no-one is seeing flickers between now and April 6th, I'll likely crank it up to be 10 years or something. That oughta learn that pesky browser.

Don

I assume by the deafening silence that we fixed this one?

If not, speak now or forever.... you get the rest.

Don

boyersmile · March 9, 2006

onethumb wrote:

I assume by the deafening silence that we fixed this one?

If not, speak now or forever.... you get the rest.

Don

So far so good.

Knock on wood. I did clear my cache after the most recent fix, and I haven't seen that pesky flicker yet. Good job!!!

Thanks,
Miles

flyingdutchie · March 10, 2006

onethumb wrote:

I assume by the deafening silence that we fixed this one?

If not, speak now or forever.... you get the rest.

Don

Seems to be fixed.

However, if some viewer visited one of our sites before the fix you just made, (s)he must clear the cache before the fix takes effect. If not, the flicker persists. After (s)he clears the browser-cache, the fix will take hold (until april 6th?).

IE6 Flicker worse now than ever???

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