Guys, this is driving me NUTS!!! 

The rubber channel or wheaterstriping in my door is causing that the window cannot run freely thru it up to the top when I'm closing the window. 

I noticed that the glass itself pushes the rubber when is going up.

I'm suspecting that the rubber is broken or loose (unglued??) from the metal rail........

2 questions:

1-- Anyone knows what's the problem here and the fix?

2-- How can I dismantle the upholstery of the door to have access to the window mechanism?

Best regards and happy wheelin'

I would first clean the channel very well with ArmorAll. Spray it on a rag and wipe out the channel carefully. Once it's nice and clean, the window should work much better. If you need to clean the section inside the door, roll the window down and very carefully pull the channel out through the window opening(leave the window up maybe an inch from bottom). Then clean it all very thoroughly with ArmorAll and slide it back in place.

Hi digger, the channel is very very clean, I even washed it with high pressure water a week ago, the problem here is that the rubber is being pushed up by the glass itself.

Here's a photo from the rubber channel just in the worst point 

The ArmorAll also acts as a lubricant. The channel is actually a type of felt/rubber and just any type of oil or silicone will just make it worse, but ArmorAll seems to be the magic potion for the strip...

Is your window 'level'?  Watch the top edge as it closes with the top of the door, as well as at the bottom.  COmpare ti to the passenger door.  I've found that my regulator (will have to take the inner panel off to view) needed adjustment (the screws either loosened or shifted).  GM showed a trick to remove the window crank by rubbing a rag across the spring clip (similar to buffing your shoes when shinning them).  It will go one with the clip installed on the handle (snaps on).  It looks to me like you will need a new window channel(JC Whitney or maybe http://www.certifit.com/index_search.htm) .

The vertical bar in the middle of the door is the piece that will need to be adjusted.  It may take a bit of fiddling to get it right.

Ok, I'll try cleaning again and using armor all after everything is clean. I'll take a look at the center leveler to check if the window is not going upward as it should.

Once I took out the window crank, the door-opener-handle frame, the pressure "buttons" all around the door's panel and the arm rest but still there was something retaining the door panel attached 

Maybe a previous owner did glued the whole thing together  hope I'm wrong   

Ok Today I did something for the window...

I learned how to disassemble the door panel, the first time I  tried didn't discovered that the door opening handle needs to be moved forward so it can be separeted from the door....

I did some cleaning, lubricating and checked the alignment of the center rail/guide. I wasn't loose (phew!) 

I uninstalled and reinstalled the whole rubber channel and tried to force it to keep in place so it can't be pushed upward..

Applied some armor all to the rubber and put some grease to the center rail...

I've been using the system some times since that and seems ok but I'll not say that too loud     

Thanks for all the advices