The Xtremer Audio isn't that bad a card as some would have you believe. The mixer mainly determines the levels for inputs like mic, line-in, midi-synth, auxillery, and for recording the "what you hear".
The X-Fi crystalizer, EAX, and 3D for headphones are enabled for both 5.1 and headphone use here. The one thing that proved to be the one annoyance was the SVM or smart volume manager option. That is the one thing left in the off position at all times here and could be what you are having a problem with.