Spontaneous motor skipping?

[Damaku250]

We appear to be having an odd problem with our drive motors.
Following an odd voltage drop resulting in the loss of control of our bot in the quarter-finals at WAT, we had discovered that one CIM and its accompanying Jag were noticeably hotter than the others.
After removing the electronics and offending gearbox, getting home and testing them on benchtop, we've noticed two things:
1) after removing our CIMs from the gearbox the one that was overheating is also making an odd clicking and is noticeably louder than the other. [Resolved]
2) that our CIMs "jump" and will randomly stop for a random duration between 1/4 and 1/2 a second. When this happens, all the motors jump simultaneously, and the lights on all the Jaguars flash yellow/amber for a brief period while the motors stall.

We HAVE tried changing the DSC and 9403 cRIO modules, to no avail.