So buy the game today and come home to play it and i throw it in and put my astros on and i get NO sound...WTF! the sound works fine on HDMI but when i switch to optical there is nothing....i cant imagine you made a game that was not dolby compliant? Whats going on here........

Ok, I beginning to think the problem is with the game because I just got done replying to this http://www.gamesas.com/index.php?/topic/1236992-sound-issue-using-headset/ about the same problem with his/her Sharkoon Surround Sound headset. This is something id Software should diffidently investigate.

OK so from the link you provided i found out that you have to de-select from Sound Settings on the XMB....weird but hey it worked.

Glad you figured it out. I'm actually using the A40s (they're amazing) as well and didnt experience that issue.