[Gunslinger]

Just set up my ATV yesterday and upgraded to 3.02 and installed XMBC was the very first thing I did.

Here's my set up. Video is passing through my Pioneer receiver and using the optical cable for the audio. All works well except when playing files encoded with AC-3. They get downmixed to stereo. Downmix is disabled and ATV says the audio is set up correctly.

Does anyone have any suggestions why this is happening?

Sorry if this has been covered before. I searched but couldn't find anything that helped.

[Gunslinger]

Maybe I wasn't clear enough. On many shows that were encoded with Dolby Digital 5.1 and shows that info on the individual episode, the audio gets downmixed to stereo.

[jmarshall]

You've specified that you have an AC3 and DTS capable receiver in XBMC's settings?

[Gunslinger]

Yes, I've checked every place I can think of that specifies DTS or anything to do audio.