The wireless link between my Panasonic SC-HTB520 soundbar and subwoofer isn't working. The soundbar is working perfectly with the TV and DVD audio input, but no link is established with the sub. I tried doing a factory reset of the soundbar, but no joy. Then I unplugged the AC power to the sub and reconnected the power cable to the wall, but again no link. One question: is the serial number of the wireless transmitter supposed to match the S/N on the soundbar? Second question: any suggestions for diagnosing the problem or fixing it?