asterisk users - Jun 2007 - Asterisk to Panasonic TDA200 with Unicall

I am trying to set up a connection from an Asterisk server with a 2 port
E1 card to a Panasonic TDA200 pbx.  We are using Asterisk 1.4.4, Zaptel 1.4.3
with Unicall.  So far we can get the E1 link up and we can send calls from the
Panasonic to an IP phone on Asterisk and even through the other E1 to the
PSTN.  The problem is when trying to send calls from Asterisk to the
Panasonic, we can only hear one ring and then the connection drops. 
Unfortunately I do not have access to the log files at the moment so from
memory the error we got said that ther was an "Unexpected MF6 signal"
before
the call was dropped.  

     I have several systemas talking to other Panasonic models like the D500.
 They all work fine.  We have basically the same configuration on those except
that we use Asterisk 1.2.X instead of 1.4.X on those.  Does anyone know what
that error message mean?  Tomorrow I will travel back to where the server is
and try again.  I will try to determine if the problem is caused by the
Panasonic or the Asterisk side.

--
Carlos Chavez
Director de Tecnolog?a
Telecomunicaciones Abiertas de M?xico S.A. de C.V.
Tel: +52-55-91169161 Ext 2001