For those that stumble across this looking for a solution, I had the same problem and have just fixed it by replacing the regulator. My drivers window was going down fine but only going up a few cm after the 8th button press each time. I had tried cleaning my switch and then a new switch before trying the regulator. I could be wrong, but as I understand it it's because the position sensor has failed so although the motor works, the window doesn't know where it is, and is not happy about moving in one go. I found that if I didn't let it go up the full few cm each time, it'll let you continously do little movements. Regulator was £30 for drivers door which seems to be the most expensive one, and took maybe a little over an hour. Hope this helps
