asterisk users - Feb 2005 - VAD (Silence suppresion problem)

Hello,

I'm trying to use Asterisk as a SIP PBX with H.323 trunk connectivity.
Everything works except that calls that comes from the H.323 side do not get
audio both ways.
Since the other way round works fine (calls to H.323 side), I suspect the
problem to be in the way VAD or Silence suppresion is negotiated. Is there a
way to disable VAD in the Asterisk for H.323 gatekeeper connectivity ?
I have tried with both H.323 and OH323 modules with no success.

Regards,

Jorge A.