No sound with my C-Major Sigmatel Device !

No sound with my C-Major Sigmatel Device !

Hi , I'm french sorry for my english , look at those pictures to show my
problem , I have no sound , but when I go to the Control Panel/Audio Devices
and Sounds Themes/Volume Control/Configuration.
I have two option , the 5.1 and the 7.1 , I have tried each option but when
I make the test I have never sound on "L" and "R" but it makes sounds on "SL"
, "SR" , "RL" , "RR" , but I don't have any sound when I want to hear music
and no sound anywhere apart from the test of "SL" ... Can someone help me
please , thank you.

Pictures of the problem.
http://img135.imageshack.us/img135/5287/capturein5.png
http://img135.imageshack.us/img135/5093/capture2vs8.png

Fujitsu Siemens Scaleo 600
Intel Pentium 4 2.50 GHz
1,00 GB of RAM
SigmaTel STAC9758/59 @ SiS 7012 Audio Device PCI