Kmixer.sys crash

Hi,

I am having problems with my system and I think it is a software issue. I am receiving an error citing 'kmixer.sys.'

I am running Win XP Pro SP2, 2 dual core Opterons, and have my box set up partitioned with the Ubuntu distro. I have tried to update to SP3 with no success. The SP3 update sends me into a vicious loop without continuing onto the XP pro desktop.

The Kmixer.sys crash happens for no apparent reason. I do not suspect it to be a hardware problem as Ubuntu never crashes (go figure). My memory seems to be just fine.

This is the msg from the BSOD:

0X000000D4(0XA4D10FFC,0X000000FF,0X00000000,OX80544D6F)
Physical dump of memory.

Is there someone who understands what may be the problem?

Cheers,

Christian