Up-Load Problems

I'm currently experiencing upload problems to my account. I've been trying to upload video's to my account for a few days now, and not having any luck :cry I've been e-mailing the help desk back and forth also, but I think we've determined that the problem lie's on my end. I was hoping someone here might have some suggestions for me to try. I've never had issue's in the past. This problem really just started. Here are the things I've tried:

1. Using latest version of Firefox and Simple uploader
2. Tried latest version of IE and simple uploader.
3. Tried both of these browser's with the "old-faithful" uploader.
4. I've turned off my windows firewall
5. I've turned off my "Norton Internet Security"
6. I've made sure all these videos are the accepted type per the wiki:
   http://wiki.smugmug.net/display/SmugMug/How+to+convert+and+format+a+video+for+upload+to+SmugMug
7. Tried resetting (turning off and on) my cable modem.
8. Rebooted my pc ALOT.

I just don't know where else to look, and hoping someone here could provide me with something to check on my PC. I'm using windows XP.