Problem is not really back.....but looking the logs History HD channl uses more PID for audio and subtitles that the FireDTV can filter.... ( Max is 16 ) and pmt is the 17th !!!! that is really a bad idea !
They probably add some languages or subtitles, it's not a change in MP.
I'll try to have a look to give pass pmt instead of a subtitle.
r22004 | ambass | 2009-03-20 17:44:15 +0200 (Fri, 20 Mar 2009) | 1 line
- Set PMT pid before other pid in hw pid filtering list to avoid loosing it when channel contain more 16 pids.
It was ..
I'm afraid there is a CAM issue that could be not able to decode 3 audio channels...
It could be interesting to know if it's caused by a MP change or by broadcaster..