Weird LR problem with duplicates

surfmonkey89

Here's my situation.

I had 1500 pictures on my laptop from a recent trip I took. I exported the catalog (including the negatives), moved it over to my desktop and imported it via Import From Catalog. Everything worked fine.

Then, on my laptop, I went through all the pictures again, tagging about 500 as picks.

I exported and imported again with Import From Catalog, with the import setting set to "Metadata and develop settings only", because I didn't want to re-import all the pictures again.

Now everything is wonky:
- every picture I marked as a pick is duplicated in my collection
- when I highlight the collection node I see the pictures side-by-side with one having marked with a white flag, but
- when I drill down to the folder level the pictures are side-by-side and there is no flag on either of them
- if I highlight a picture and go to the Edit menu, the Delete option is grayed out so I couldn't delete the duplicates if I wanted to

So my questions are:
- what did I do wrong on import?
- related to the above, why do I have duplicate pictures if I specifically said to only import metadata and develop settings?
- why do the flags sometimes disappear?
- how do I get rid of the duplicates?

I have no idea what I did wrong; this seems like a pretty straightforward scenario. Any help would be greatly appreciated.

thanks,
paul