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.