I have a Pioneer DEH-P740MP HU and the GEX-903 XM modulator connected via the IP-Bus cable. This worked fine for about a week or two. No problems. But NOW the XM will only play through the right side speakers of the car. (The sub woofer also gets a signal) I can't figure it out. The FM radio plays through all speakers, the CD player plays through all speakers. This leads me to believe it is not the head unit. (Although this HU has been in the shop twice for not producing power and not producing sound) (Under warranty of course) It could be the IP-Bus cable itself but I think this is unlikey. If the cable is faulty then odds are the whole signal would be bad not just left side input. It could also be the modulator itself but I don't know how to isolate this problem. Antenna problem??? Maybe someone has some insight out there. PLEASE HELP. I am losing faith in PIONEER big time. This HU has been a nightmare for me so far.