Yeah, i've been having this problem as well for the last several years
with my 2000 Civic but only last year did the window somehow manage to
come off of its track. I've taken the door apart twice, lubricated the
arms holding the window with grease and tried running some oil (not
motor oil) down the tracks to help. No improvement. Perhaps this
winter, when it happens again, i'll try some silicone along the tracks.
During the summer, the window is perfectly fine.

-AGS