Come the think of it...if the throttle position sensor were intermittently providing a noisy signal, the PCM could be confused into providing too little IAC at closed throttle (thinking that the TPS was at part throttle due to an incorrectly-low ratch). Then, when the clutch is pushed in, it will go to the wrong adaptive table, and PRESTO engine stall. You could be on to something here. Another data input to monitor the next time that I try to capture this failure. It has been about 4 months since my car has done this last--I've been averaging about 6 times a year.

1999 Contour SE Sport MTX75 T-Red/Grey
Audio: Pioneer DEH-7400MP (MP3 CD), Pioneer TS-A6857 front & rear, PPI PCX-250, Infinity Perfect 10.1
Other: cup holders, cargo net, Blizzaks, Potenza RE950s