What happend was that I had received the unit with an earlier firmware. Updated the firmware and all was fine until the actual card had a blown capicator. This was verified by essentially moving the AUX channel card to the front left right slot on the backplane of the unit, this caused the problem to completely go away. Its great to see solid engineering in that ALL 7.1 channels essentially use the same cards, so they can be swapped out - remember that the label on the card FR, C SUB, Rear etc etc are only labels - the actual card slot determines which channels are routed, so tyou can take an aux and swap with the rear etc etc, the only subtle difference is the subwoofer channel which needs to have the crad's toggle switch moved to subwoofer.
Upgrading the firmware involved creating a DOS bootdisk, this can be easily gotten at www.bootdisk.com - then running scom (low level tranfer utility) and upgrading the os first, then powercycling the PDSD and then upgrading the DSP code and powercycling. If you need instructions I can email them to you. You will need a communication cable to RJ11 which you can have made, it must be straight through. The proceed service guy verified with me that these cards are prone to blown capacitors over time due to heat - which makes sense if the Front left right and sub blew first since the guy I bought it from was a heavy 2.1 type of listener.