I also had the same problem (couldn't activate sirius). After trying various things the following finally got it working:

1) Turn on the car and radio.

2) Turn radio to Sirius (display shows the "to activate your Sirius call...")

3) With the car still running, log onto the Sirius website with your account/password. Click the ESN link at the bottom, and then the "re-send activation signal" button. (I think you could also call Sirius and have them re-send the signal instead of doing it yourself.)


-C.