Shoutbox

I guess that the three on the back are the same as mine.

The two on the front, would work the same as two on the back when something's plugged in, and cut off the ones on the back. When nothing's plugged in, the ones on the back work as normal.*

For example, you can have your speakers plugged in the back, and whenever there's headphones plugged in at the front, the sound comes through the headphones, otherwise they come from the speakers.*

* purely hypothetical and based on abstract reasoning.

Do you actually have a 5.1 surround speaker setup? If you don't then set your SoundMAX Control Panel to stereo speakers or steroe headphones. If you do have a 5.1 surround setup, the only way to get microphone input on you computer is to run the speakers 2.0 channel.