Just posting this in case someone else comes acros the same problem and searches for a solution.

I've just installed Mandrake 10 on an Hp NC 6000. Everything ran smoothly, X with the ATI Radeon fglrx driver.

One issue was sound. Upon boot the machine would emit a very loud screeching noise. Unfortunately plugging in a headphone plug does not mute the speakers on this model.
I've found that this is caused because the mixer has the mic interface set to wide open. Mute this and your problem is gone.
I've used the snd-intel8x0 driver without any special settings. One peculiar thing I have noticed is that on volume control the PCM and PCMM2 slider control the headphone output and the volume slider controls the speakers.

Hope this helps someone.

Jeroen

Another solution:use the intel810 driver:P