Needed new window regulator AGAIN! Why?

[djcamera]

Hi from Atlanta. I'm the original owner of my 1998, got it new in Germany. I just had to replace my driver's side window regulator for the third time. Through the years, the glass has popped off-track several times. It goes "CRACK", then there's a sickening glass/metal grinding sound, and if I'm lucky, the glass doesn't fall down into the door. I can grab it, jam it with two hands back into the track, and fiddle with the control button until the regulator catches and holds it. Always one of the regulator "scissor arms" is bent. I've had fix-it guys force the bent part straight, replace the fuzzy tracks, use a different type of grease, and sometimes just replace the whole damn regulator.

Just a few days ago, it happened again, and I coughed up $450 for this car's THIRD regulator replacement. Everything about this car is tip-top, but the DAMN WINDOW won't behave!

So, hit me with some wisdom: what makes these regulators bend so often and apparently so easily? (Only the driver's side is a problem) I'm not Crazy Window Guy, I just use it normally. And the part cost about $110, the labor $340. Seem high to you?

Thanks.
DJ