[Tim Arnold]

This is going to sound stupid, but its just a sanity check... have you tried swapping the input and output wires connected to the controller? We wasted an incredible amount of time when we first hooked ours up last year, as they were backwards. The whole board lags incredibly/won't run if they are incorrect.

Also, double check any solder points or female-to-female PWM cables.

We ordered 4 rangefinders off VexLabs last week and successfully implemented them without any problems today (EasyC Pro, though), so otherwise I don't know what to tell you.