Sounds like the little clamp thign that the window sits in or bolts in is busted on one side or lose. You might want to try retighting the bolts a little and see what happens.
97 Mystquie GS - I4 ATX died at 168K
94 Pontiac Crap AM SE - 2.3L I4 5spd
2002 Mazda Protege5 - 2.0L ATX
