Hi,
I had a ordinary home box fan trigger the "on change" pins on a PIC one time. Instead of looking into it electrically however i changed the program to make it be able to deal with getting faux on change interrupts. The fan was of course completely isolated from the PIC chip because it plugged into its own AC outlet. So the pin must have been able to pick up the inductive spike when the fan was turned on or off. Funny if i wanted it to do that it would probably take a week to get working
I never had one reset though and i've operated in some pretty noisy environments. But other folks have had the same problem with the on change interrupts as you can read on the MC site.