Ive got an FT450 that I run HRD on. It works great on my laptops. 2 of them. When I bring it over to my PC to control it from there, it says "failed to read frequency" so It's not interfacing with the radio. Im using windows 7, a prolific chipset adapter, and a serial cable. Ive got the latest drivers for it also. Rig works fine with both laptops and the same USB to serial adapter. Connects instantly. my PC won't connect to it at all. Suggestions?