[ray1112]

Code:

<audio>
   <streamsilence>1</streamsilence>
</audio>

In my case it's working (I also update XBMC night build to 12.0-ALPHA6 Git:20120917-a61cb73).
I started XBMC, checked sound (OK), turned off AV receiver (I didn't shutdown XBMC).
At morning I turned on AV receiver and sound is OK.
I checked music and BD movie (DTS-HD MA).
No ERROR messages in log file.
Edit: HD music are OK (flac stereo 24x192, flac 5.1 24x96) also.