Can you link some of the vids that do not work. I am starting to wonder if some of the problems are related to certain vids or not.
I still think CMSS 3d is seeing 5.1 audio and not messing with it. CMSS 3D off is still playing on ALL speakers(X-Fi titanium fatality. Latest Beta, Win8). Switching it on and off does not even change the sound at all like it does with any 2 channel stream.
seems to have 5.1 in the video it self.
http://www.youtube.com/watch?v=ddC6GEHAlkg
Now at the same time I can go to this vid and only get 2 channels, but as soon as CMSS 3D is switched on it plays on all speakers.
Seems to have only 2 channel, but works with CMSS 3D.
http://www.youtube.com/watch?v=1X-g0iDvS3M
This leaves me wondering if some companies are playing with the 5.1/7.1 ability offered in flash.
As for the question about older versions.
http://forums.adobe.com/thread/1022066?tstart=0
HUGE EDIT.
I was playing with onboard sound and none of the videos had 5.1 sound. Not even those that have 5.1 on my other pc. On the above page you will see
"How do I do a clean install of Flash Player?"
http://forums.adobe.com/message/4041846#4041846
After performing that, the 5.1 vids now have all speakers even on onboard sound. That said 2 channel ones are still only 2 channel, but thats fine because CMSS 3D will fix that for X-fi/Audigy users
So that is the answer, clean install flash.
This also explains why my Win8 system was unaffected because it started with a new version.
Hope this helps someone.