VIAHardware has publicised the MSI BIOS bug in WinXP so our buddy"s at M3Dzone got there hands on a BETA bios that should fix the problem.
"Please take note however that this is a BETA BIOS that is intended to solve MSI-6330 family of Boards with BIOS IO-port addressing in Windows XP and that v3.0 be installed 1st before applying this new BIOS update".