asterisk users - Oct 2004 - How to force G.729 in H.323 calls

Sirs,

I have the following problem:
I'm working with H.323 and in my h323.conf file (within the general
context) declare
disallow=all
allow=G729

but CLI shows:

*CLI> h.323 show codecs 
Allowed Codecs:
         Table:
   G.729A{sw} <1>
   G.729{sw} <2>
 Set:
   0:
     0:
       G.729A{sw} <1>
       G.729{sw} <2>

And my asterisk first tries to negotiate G.729A and not G.729 as i
declared in h323.conf.

How can i force Asterisk to use ONLY G.729 and not G.729 A?

Thank you in advance,
Juanjo