My passenger side windows failed open a couple years ago. Had the motor & drive assembly replaced under warranty. I don't think it's common at all so you shouldn't worry. But if your windows are frozen shut and you hear that popping sound when trying roll them down, that's the gears skipping. It's unlikely you'll destroy the motor, but if you strip the gear, it's just as bad.
I live in canada so I get frozen windows a lot. Hot tap water in a bottle is your friend! Pole a hole in the cap and squirt it at the edges of the glass where it's frozen. You'll defrost it in a minute
