Temporary freezes but game doesn't crash

It seems some people have had total game freezes, but my problem's a little different. When playing sometimes my computer freezes for about 30 seconds. Mouse locks, keyboard locks. Then it recovers. During this time my party are unaffected and carry on playing. It's a bit of an inconvenience when they rush in to a mob and suddenly the Healer gets locked of helping!!

Any idea why this is?

System:
Win2000
AthlonXP 2500+
1 Gb DDR400
Ti4200, 8x AGP
SBLive!

What else is running in the background/system tray? And try closing them all and play to test it.

The usual fiewalls, viruskillers. MSN messenger is often running. I'll kill that next time. Cheers.

I also get it