5.1 and 7.1 via Optical Out Playing Games
I have an issue with no surround (5.1 or 7.1) sound being output through the optical output while playing games. It's as if the games are only outputting multichannel audio to the speaker outputs. If I play a DVD with 5.1 surround, then the optical DOES output surround sound with no problem, so it is working. The optical output is connected to a HT receiver (Yamaha HTR6180) and the settings on that end are not the issue. My motherboard is the ASUS Crosshair 4 Formula, and cpu is an AMD1090T.
if optical out is selected as your default output there is no real reason why it shouldn't work, unless the game uses its own sound engine like dirt 2 or crysis.
you have went in to control panel and set it as the default output. (controlpannel/sound) on the system audio controller. not just your sound cards panel.