My driver's side window won't go down that half-inch when the door's opened. I have already tried to reset the regulator but it still won't work. It's really annoying because it now catches on the trim then pops back in a minute later...it can't be good for the window or alignment!

Any ideas on how to fix this? :help

Than the switch that initiates the lowering is worn.
You have a 325 I see. Than yours is on the door itself (where it catches the striker) on newer cars, the switch is on the striker. I can manipulate it by hand with the door opened.

Sometimes, a squirt of WD40 might also do the trick.

Thanks MParellel!

Just to make sure we're on the same page, on 328's I manipulate #6, but on 325's I need to play with a part on the door. Which part is it?

http://img81.imageshack.us/img81/8272/50322272xy1.png

That I don't know as I have never seen it. But if it "opposite" part as on he newer cars, so instead of the striker, it's on that part that cathes onto the striker.
So somewhere on part 1.

You can either build up the part on the striker that contacts the switch as in this post:
http://forums.bimmerforums.com/forum/showthread.php?t=850900&highlight=microswitch

or replace the microswitch which is a little PITA. search the forums, its been discussed before. I've been dealing with the same problem on and off for years. Mostly when it's cold outside. been to lazy to replace the switch. think im gonna try to build up the striker first.

That thread you posted was mine. I actually built up the striker AND the microswitch with the JB Weld so I didnt have to repace anything. The microswitch was more worn down and I just did the striker even though it was only a little worn. hope this helps.