5.1 Speaker Help!!!

[Fender357]

I just got a set of Logitech z-640 5.1 surround speakers. They sound really good, but I'm not getting any sound out of the rear speakers.
But...it still plays the sound of the rear speakrs in the front speakers, but it plays it backward....right sounds on the left and left on the right.

The front speakers play like normal as does the bass.

Does anyone know how I can fix this?

Oh...and the way I'm testing my speakers is with CS:S. If some of you didn't know...you can go into audio and hit test speakers, it opens up a map and has a really really cool way of testing you speakers.

Please help me quick!!!!

 

[Fender357]

I've messed all around with the wires to make sure everything is where it should be and it is. The three plugs are in the right slots. And if I plug the back speakers into the front jack I get sound out of them. But my computer dosn't seem to care that I set it to 5.1 speakers.

 

[Fender357]

Come on! Help me out here!

 

[Doombringer]

HL2 seems to have a serious problem with more than 2 speakers. I have a 4.1 setup and it hasn't worked right in CS:S and now not in HL2 either. The sound its jittery and clicky/poppy. If I set HL2 to 2 Speakers or Headphones it is beautiful.