BL7 0nboard sound problem

Ive got a problem with the onboard sound card on a Abit BL7 it plays sound fine but when i plugin a mic i get sound out the speakers and thats it?

Ive checked in the multimedia devices and the Record device is set to the same as the Playback device this cant be right can it!! ,, but that is the only device avalible

any one else had this problem and if so how did you fix it?