80's chevy window problem

It's a mid 80's chevy truck with the drivers side power and the passenger side manual. Yeah, I wish that was reversed but...
I just put new weatherstripping all the way around the glass including the channels. About a month later (and for no apparent reason) the glass is jumping out of the track about half way down when I'm opening it. This is the powered driver's side. It seems like the glass should stay in the front track going up and down but now it just floats (and bangs around) between the two tracks. I have tried to squeeze the two tracks together but know this wrong.
I have the interior panel off full time now because I have to shove it into the front track then hold it forward as it goes up. I don't see anyplace for missing bolts or clips and I don't have another door other than the manual passenger side to check and see what it should look like. I have a Chilton but it doesn't say much about this.
Any help would be grateful! Thanks!