I have an MSI PT 880 NEO-LSR (6 Channel AC'97) and a newly purchased SONY HT-DDW700 home theater system. Using the Digital Coax out from my PCs onboard sound card, i have only been able to use 2.1 through the system. Does anyone have any advice? The SPDIF outputs are active, but windows wont let me adjust the level from the volume control....yet the system still receives 2.1 sound. Help. I just want to play HL2 in surround...haha