did you fix it yet? it may not just be off track. the teeth on the control arm may be broken. my window is like this now and my cousins was. he had to replace the window control arm to fix his. this problem sounds similar anyway, the window will go up (depending on how many teeth are broken) and then fall alittle. if it's off track you can take the door panel off and loosen the track screws at the bottom and move the tracks. sometimes u'll have to find something thin to slide down the window track making sure the rubber outside part of the track gets on the outside of the window and not folding behind.