Hi Patrick,
Since you mention that the other software works fine, we should be able to get the OBD Diag to work also.
Couple of questions to help diagnose the issue
1. Connect to the OBDPro via hyperterminal and set the protocol to Auto by typing in ATSP0. Then type in ATZ to reset the interface and then type in ATDP. The interface should respond with AUTO.
2. At this point shutdown hyperterminal and start OBDDiag and see if this fixes the issue you are having.
What vehicle are you running this on?
Let me know if you still have problems and I will dig into this some more.
Thanks
Paul
OBDPros