Back to the question of MOH, take out the codec issue in troubleshooting. It seems to me by default MOH server supports G.711u only. If your H323 gw voip leg is configured with G729, probably you won't hear any music when being placed on hold. you can check it out easily by putting "codec g711ulaw" explicitly in voip dial-peer. Then see whether the problem is resolved. Or you can go into service parm of Cisco IP Voice media streaming app->MOH and highlight the G729 codec.
My knowledge of call drop is that the h323 gw does not support H245 empty capacity, which is essential in swapping existing RTP audio channels with others. But since yours is running 12.2(1)T, it seems to be ruled out. If you like, you can send me the h.245 and ccapi and I can take a look at them.
These are the paths to get to each CCX logs through CLI. They may be helpful if you are having issues accessing RTMT or downloading logs through it.
If you want to download them you have to prefix "file get " and you can add one of the options (re...