I just uploaded some pics from Crag Lake, all were resized to 2000x1333, but still the thumbnails are broken. I forced it to regenerate them but now it's just different ones that are OK and broken. It's also very slow, do I have to re-try at 4:00 AM or something? I'm really tired of this crap :banghead::banghead::banghead::banghead::banghead::banghead::banghead::banghead:
How many images did you put up? FWIW, I've always had good success ( as in no broken thumbnails) adding 10-15 images at a time when creating galleries.