Just to confirm, audio is still echo-ey when running in stereo through receiver AND when directly connected the tv.
I really don't want to have to get another graphics card to fulfill this simple function, is it the beta drivers I'm using? Is someone from Intel able to identify WHY their drivers won't install for most users?
Please post the dxdiag report from your system and test using only a direct connection between the PC and the TV (no AV receiver in between).
You may also send some screenshot of what you see in Windows* sound properties to see what is the default playback device and also what is seen in the Sound controllers category of the Device Manager. (Please post them here, not through a third party site)