I think you and this guy should communicate about your adapters and possibly the USB ports on your phones:
http://forum.ppcgeeks.com/showthread...=audio+adapter
Is yours really an HTC adapter, or does the "WELL" indicate a 3rd party adapter that is supposed to be compatible with your Touch Pro?
Edit: does the stock HTC adapter (the big one that came with the phone) cause this issue? If not I'd say it has to be the adapter.