Sirius Radio Failed?

I've had a Sirius retrofit in my '01 530i for about 5 years now - working fine. Recently (last few weeks) the display flashes ACQUIRING almost everywhere (including in our driveway with a clear view of the sky). I originally thought it was the antenna so I bought a new Sirius (Dot?) antenna at best buy - the connector was a very tight fit but I got it to fit into the brown plastic connector on the radio in the trunk - except there was no change in the symptoms. I can get a signal in a few places so I drove to where I could get a signal, tuned to channel 184 and called Sirius and had them re-send my activation signal. I waited there for about 15 minutes, verified I had audio on all my channels and drove away - only to have the same symptoms. I have a Sirius radio in my other car and it gets a signal just fine all over town. My questions are:

1) Was the best buy antenna a valid replacement for the one that came with my retrofit kit (PN 84-11-0-399-301)?

2) Is there any way to perform a hard reset on the Sirius receiver (other than unplugging power which I've tried)?

3) Can the dealer test the receiver and/or the antenna and definatively tell whether or not one or both have failed?

4) I've seen some information on the MB forums that maybe Sirius' recent channel re-alignment caused some incompatibility with some of the MB Sirius units that required a firmware patch - can this be confirmed and is it possibly happening to the BMW units?

Any help or advice would be greatly appreciated.

TIA,
David