I just spent a couple of hours on this issue.. I imported a gig of photos from my 10D into Album 2.0, after the import screen had completed, I turned off the camera (it was no longer flashing busy), and I proceeded to click STOP when album screen changed to importing the photos (thumbnails) into the current catalog... I shouldnt have done that apparently.
I cant find the photos on my harddrive that I just spent half an hour importing over a slow USB1 connection. I even went as far as searching the drive for .JPEGs and .CRW files on date, but no result?! Did PS Album delete my photos from the drive when I clicked stop to updating catalog with thumbs?
Only the two photos or so that completed thumbnail process is in the selected import folder.