Is it as bad as some reviews make out? I've got the choice of partnering the graphics card with either my current Fortissimo II sound card or my DigiTV card. Nebula have released software to allow streaming the TV multiplex over the network, which is why I have the option. I'd rather keep the DigiTV in the Shuttle though.
Maybe an external USB sound card is an option? I only have a 4.1 setup, Create FPS1600's I think (quite old now).