asterisk users - Oct 2005 - TDM04b to SIP extension not ringing (sip to sip works fine)

All,

I have a TDm04b card an 8 SIP extensions. Calls come into the TDM and
are answerd by the auto attendant. When an extensions is entered I see
the Dial(SIP/100) on the console but the phone never rings...

I can pick up any extension and call 100 and it rings just fine and they
answer and everthing is fine. All 8 extensions can dial 9 for an analog line
and call out just fine.

I just dont get ringing on the SIP extension for incoming calls.

What have I overlooked?


Thanks

Jerry