unable to get sound ATI wonder by using ENcoder

Ok i have my tv receiver connected to the computer using Encoder.
The video is very good but sound is not working.
I think the problem is when i click on config it give me option for
MONO MIX.
But when i try to change to LINE IN the apply button is already
clicked.
Other else id ont no wt is the problem
Need hemp on that immediatly