No trouble with preview here, and I think I'm on the latest version of Firefox, paired with XP.
So Robert, I didn't see it mentioned above, but would it be possible for a future upgrade to offer in addition to the "See Full Size" option another one for "See Thumbnails?" Just a thought that maybe instead of using the arrows to view each picture, we could select from the thumbnails those we'd like to see in a larger format.
Thanks so much for this latest feature! Picture laden threads are opening up in a flash on my tired old laptop!