For my part I have acquired an XP 2000 + with an ASUS A7N8X Deluxe motherboard with chipset NVDI, it's a big mess and impossible to make a recording without cracking. Also using my Line 6 POD XT connect via USB for recording my guitar is even worse.

what do you use as a motherboard without cracking or disturbance recording?

That said, the Athlon XP 2000 + does not seem to be implicated directly, but it is especially the Nforce 2 chipset NVDI semlbe who screwed up a lot with the audio ....