asterisk users - Aug 2007 - How to debug OH323 Channel (version 0.7.3)

Hi all,
I got serious problem here, I hope I ask on the right place here (sorry if I 
am wrong).
I have used asterisk 1.2.17 with openh323 ver. 0.7.3, for integrating 
between SIP Gateway and H323 Gateway, it runs about 6 months. But, recently 
I think it doesn't work anymore...I can't call from SIP Gateway to H323 
Gateway. I try to debug oh323 by using :
# oh323 debug toggle
But I got no info about what happen,
please give me a clue or something (url) for troubleshoot this.

Thanks,
Hadi