I have my pc hooked to my hdtv and surround system.Using SB 5.1 live card.I get sound ok but not true surround.I have 3.5 hooked from digital out of card to coax digital in on reciever.I get 2 channel sound great with this setup.I have downloaded several 5.1 surround sound files and test files to check if decoding is working.I have turned on digital output only and turn off ac3 .Any one know what i might be missing ?