NForce driver issue

[Cerb]

Foobar2000 skips every minute or so. There is a CPU spike accompanying the skip. It is playing over the network.

DFI Ultra-AL (Nforce2 Ultra 400)
1800+
512MB RAM
Philips Aurilium USB soundcard (worked skipless in previous NF2 mobo)

Windows 2000 SP4
Nforce drivers 4.27 (same behavior in 4.24)
USB driver 1.2.2.1

It occasionally seems to occur during input from the keyboard. I've tried changing network speed settings, network optomization (CPU|throughput) changing USB ports (to the mobo header ones), and changing various process priorities, to no avail. Any ideas (aside from copying the files to my HDD, though I am doing that for de facto RAID 1 )?

 

[Cerb]

First, BUMP.

Second, is there any way to get the USB controller on its own IRQ? I've forced it to 10 according to the BIOS, but it still shares with the RAM on IRQ 20.