Audio stutter with live tv

[zjed]

Hi all,

I'm am building my first htpc and have not been able to solve this problem for around a week now.

Setup :-
asus a8n-e mb with onboard spdif (using optical)
dvico dual HD tuner
denon avr-1705

While watching live tv, some random channel often has the audio stuttering or occasionally no audio at all. When stuttering my av receiver has the "digital" signal on and the DD indicator flashs in time with the stutter. This occurs using either FusionHDTV or MCE.

When I switch channels then switch back the problem may dissappear, if I keep changing channels I can eventually get back to the problem channel with the audio working with the DD indicator on the av receiver on. My other option at the moment is to chaseplay the program ( press pause then play).

If I record the program with the stutter it plays back without any problems.
This only occurs with live tv, all other play back sources do not have this problem.

I have dvico audio set to "spdif+waveout", asus mb is set to spdif for digital & analog, MCE audio is set to spdif.

I presume this is a problem with the audio codec but I can not even work out which codec different programs use. Is there a way of telling/setting which audio codec is being used? Is there some other area I'm missing?

Any suggestions would be appreciated.

Thanks