Sticking clutch pedal

[flouese]

Whenever I put my car into reverse, the clutch pedal sticks in the "depressed" position which forces me to release it with a quick pull using my toes. The pedal only sticks when I go to reverse. Slave cylinder, clutch, pressure plate fork, IMS changed out several months ago, system bled with a power bleeder and the car brakes fine. I have a new master cylinder standing by in case that is part of the problem. Any thoughts.

99 base w/5 speed and 168K miles