Hi

I have a X-Fi xtreme Music sound card and DT 234 Pro headphones and some standard speakers (2, 1 left 1 right).

The sound card has 4 channel jacks at the back, 1 is mic/line in, the other one is a green one that says FL/FR, this being the one i plug my speakers into, then there are two others.

Now my problem is i can only get my headphones and speakers to work in the same channel jack (the green FL/FR socket) i want to be able to plug both my speakers and headphones in, and mute the speakers when they are not needed via the creative control panel. ANy ideas? what am i doing worng.

That's because the green jack is for FL - front left and FR - front right. Most of the music and stuff you are listening too is probably in stereo, so, unless the creative control panel has an option to put a stereo signal out to all channels, there is no way that the rear outputs are going to put out a front channel signal.