Some Insight

With the help of Ted Kruger of RPI fame who was in town for a lecture, we seem to have discovered the gremlin's lair.

The whiskers were running on a 9V circuit separate from the motor drives, and as such I didn't consider them a source of overload. However, when the devices get really worked up, after say 5 minutes of interaction and movement, there is a chance that two of the 9V whiskers could come in contact with one ground - creating an 18V potential that would cook a 555 timer...