asterisk users - Jan 2005 - grandstream sip phone calling Zap/1 on TDM20Brings and answers but not hear voice

Here is the console screen.

Starting simple switch on Zap/1-1
Executing Dial("Zap/1-1", "SIP/403") in new stack
Called 403
SIP/403-9c60 is ringing
SIP/403-9c60 answered Zap/1
Spawn extension (smvoice-incoming, 403, 1) exited nonzero on Zap/1-1
Hangup Zap/1



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I have a grandstream 101 that is calling an extension on Zap/1 of a TDM20B.
The grandstream 101 can call another grandstream 101 at a different 
extension- that works fine.
The two phones on TDM 20B can call each other.- no problem.When I call 
the TDM20B Zap/1
from the grandstream phone it rings - I answer and I dont hear any voice.

for the grandstream I have tried allow=all for the codes but made no 
difference.

Any ideas on what I am missing?

Thanks,

Jerry