When overclocking my 4400+ on my Vista machine (with Windows Vista Ultimate 32-bit), I started getting 0x000000FC Blue screens. Debugging the memory dump told me that it was amdk8.sys which was causing this. Since I'm not using C'n'Q I used Autoruns to keep it from running at startup. This fixed my problems.
Now, my question is: Is there a problem with amdk8.sys on Vista in general or is it just something wrong with my machine?