I recently printed some pictures on glossy photo paper (make by Hammermill) and they look great, but when I put them in the frames, I noticed they tend to stick to the glass in a few spots, making it look like there's water on them or something. The pictures and the glass were definitely dry and clean. Is this a common problem? Do you know how I can avoid it? They were printed on a hp deskjet 845c printer.

I can't understand why this would happen if the paper has been left to dry for long enough. Sounds like you've just got areas on the paper that are too saturated with ink. Does the same happen if you print on a lower print quality?