hi guys, i have a quad g5 and have recently hooked it up to a 5.1 surround sound amp via the optical cable. i have so far been unable to get anything other than stereo output from it though. the amp supports up to 96khz and there is definitely nothing wrong with that as ps3 works fine with it. when i open up audio midi setup though and go to configure speakers all the surround sound options are greyed out. any ideas would be much appreciated.