I'm also kind of wary about chain auto parts store testing. It all depends on the employee doing the testing. All of that aside....
It IS very weird that you're ruining DIS modules like this. As the others have suggested, check all of your grounds. Check for proper installation, good contact surfaces, frayed wiring or poor connections, etc.
I've gotten into the habit, after working on a few V6 cars that had ignition/random no start issues, of attaching the ground strap from the firewall to the crossover tube bracket, as opposed to the factory stud location. There were really only two cars that this solved a problem for, but it's one of those things with me, once I run into it once it's always on my mind as a possible problem.
Aside from that, the normal DIS stuff. Heatsink paste as mentioned, make sure all 4 screws are in, in good condition, and secure.
If all of that stuff checks out, I'd start looking, again, for pinched/frayed/shorted wiring somewhere. Perhaps there's a temporary short that only occurs with the normal movement of the drivetrain?
I'm not going to beat a dead horse, but I will say that I think if there were a "SHOForum most improved" award, you'd be on the top of the list, Zach.