Hello All friends

I have 2 machines that the knoppix 4.02 can not play sound files on them:
1- Asus motherboard model "P4P800 SE" +P4 2.4GHz + 256 RAM +Bios: AwardBios Ver:1004.003
On this machine the knoppix 3.9 has no any problem with sound activity but knoppix 4.02 detects the sound card and all of sound modules (such as kmix and kde control center ) act normally but no sound is heared.
2- GigaByte motherboard model "8I845"
On this machine all versions of knoppix perrior to 4 had no any sound problem but with knoppix 4.02 the sound system has same reactions and problem like the above(asus) motherboard.

Has anyone any solution ?
thanks