one more update: the bsod complains about failure of ativvaxx.dll at address BF56E2E. Interestingly I can get EPG information and some sound from the selected channel, and immediate crash when MP is about to display the tv.
1) Make sure that you are using the latest ATI drivers
2) Try disabling HW acceleration for mpeg2 decoder
3) Try more powerful power supply
4) Run some memory tester for one night
On your first Post i can see that you haven´t selected a MPEG2 Audio Codec and you are using the cyberlink codec als MPEG2 Video Codec. I would try setting MPV as MPEG2 Video Codec and MPA as MPEG2 Audio Codec in the MediaPortal Configuration. The Settings are in the Television or TV-Client Section.
I have the same motherboard as you. I also had big crashes (BSODS) with the cyberlink 7.3 codec. I found it was due to having enabled hardware decode for mpeg2 and h.264 in the cyberlink codec setup. Presumably the cyberlink codecs dont like the HD3200.
Now I'm using the cyberlink 7.3 codec for MPeg2 without hardware decode and I bought the coreAVC codec for H.264. Now I get a pretty good picture on my TV via HDMI for SD and HD formats with screen set to 1280x720.
I still get occasional crashes but these are now elsewhere in the UI rather than when trying to watch TV.
I also have the latest bios (F4) the latest mboard drivers from gigabyte and the catalyst 8.5 graphics driver.
If you decide to flash your bios DONT do it from the gigabyte windows app. - it might well ruin your day. Do it using the tool in the bios setup screen.
I solved my problems by selling the motherboard and buying a nvidia based system and a Geforce 8800GT graphics. According to this forum: Freeview DVB-T compatible videocards. ATI still has some issues with the graphics driver and it was causing the system crashes.