We found the problem - referenced a custom PID class in the .h and never instantiated it in the .cpp - insipid little thing. I actually got dangerous enough using the debugger to have it point toward the exception's root cause. Everything works great now. Huzzah and such.
Thanks to both of you for the advice. We actually reimaged the cRIO. It didn't fix the problem, but it never hurts to eliminate that particular uncertainty from time to time.
