windows jamming

[dieselal]

I took my 2002 a6 to a garage to try to fix the rear windows as they seemed to be jamming on the way up and then the anti-pinch device would kick in and shoot the window back down.
The mechanic explained that the windows were binding whilst being raised and He cleaned the channels , greased the mechanism and all worked fine until I tried using them again last night.
The windows will drop as normal, but after a third of the way up during the closing, They seem to bind and twist off line a little in the widow frame . The only way to return the window to the top is manualy assist it by pulling the window back in-line whilst raising with the other hand.
The car has never been dammaged and I am :confused: can ayone help?
thanks :beerchug:

[dieselal]

After cleaning the felt/rubber window guides in the top of the door with some wd40 soaked into a cloth and used with a screwdriver to run around the inside of the runners, I have got the windows operating as normal.I am not impressed however with the mis-hap in the first place, I didn't expect this on a car of this standard.So I just hope that this solves the issue.:confused: