Onkyo 605 Advice, possibly windows related?

[SoliD]

Hello, I run my PC through my Onkyo 605 amp, utilising HDMI out, this I have no problems with, however if I just want to use the audio, HDMI appears disabled, so I am using SPDIF, which isn't a problem, however it seems that I need to turn it on/off constantly to get it working, ie playing one track will be fine, at the end of the track it will stop working, so will need to disable/enable, then the next track might start working.

I'm not sure if I have set something up wrong in Windows (7), I am using the spdif on my motherboard which is a Gigabyte GA 965.

If anyone has any ideas much appreciated.

 

[lucid]

This isn't normal behaviour from an SPDIF-connected source. Nor is there any sort of communication back from the amp to source via either coax or optical that would provoke this kind of behaviour. So I think your diagnosis is correct. There's something within the O/S or the way the PC is set up that means it is switching back to HDMI audio out after playing a track.