No sound asus a8nsli

[zypheruk]

Hi folks first time asking for help here, I have a weird problem with sound, first up its an a8nsli amd motherboard running 10.5.6 and i have ac97 sound installed and working fine.

Now i bought an apple slim usb keyboard, and it works fine also, but to get sound i must have my old ps2 keyboard plugged in at same time.
I have done a fresh install several times and same problem,

Any help much appreciated.