I recently installed the newest version and this totally broke my current 5.1 surround system configuration (again). Whenever I have a media player (WMP) playing some audio file then IF I open Firefox (and load any page with zero flash content) the sound playing in the background will only be output from 2 speakers instead of all my 6 speakers.
It's like the Flash Player via the plugin container auto allocates itself as first audio priority over my currently playing audio file even if no flash content is being played whatsoever. This happens everytime I open the browser after maybe 2-5 seconds, if I close the browser the audio will play again on all 6 speakers. The issue is somehow related to my previous thread: http://forums.adobe.com/thread/1020579
11.6 caused no such issues. 11.8 beta doesn't solve it either. I'm using a fully updated Windows 7 x64 if that matters.