I have a problem with the driver's side door on my '92 190E. The lock is just a confusing mess for me. The lock won't turn counterclockwise but it will turn clockwise. With the clockwise turn, the lock knob on the inside moves slightly. I took a look inside and played with the vacuum pump which is fine. It moves up and down when I use the passenger side door from the inside anbd outside. However, when the door on the passenger side moves the sliding sleeve down on the pump on the driver's side, the control arm (connected to the lock knob and mechanism for the door latch) comes out of the sliding sleeve. So, since this happened, I took a look around the mechanism that is connected to the tumbler and the control rod, and it would not move. Felt like it was stuck in place. Any ideas what is goin on? Thanks in advance.

-Andrew