ditto.

i can appreciate finding a definite 'cure' to this, as well. in the meantime, try the silicone spray. mine started to run slow and eventually were tilting forward and pulling the rear gasket into itself when going up. i did the following thanks to the forum/mechanic's advise and the windows have been behaving nicely, since.

run a wet rag (may want to use a screwdriver or butter knife underneath it to get inside the rubber gasket) through the rubber channel and wipe as clean as possible. you may be surprised at the amount of crud coming out of there. this may take you a few times. once done, spray it generously with the silicone spray. this should help.

hope my feeble attempt at explaining came across ok.

good luck!

-jose