XP is much more fussy about hardware than Win98. However, the problem shouldn't be the motherboard or XP-M. I'd look closely at the RAM (reseat, try another module or one at a time, try diferent slots, etc.), RAM timings and other things. It's a good idea to first memtest the system and tweak the BIOS. When you are error free in Memtest86+, XP should install.
-------------------------
K8N Neo2, Opteron 180, 2GB G.SKILL PC3200, 9600XT, Cooler Master CM 690/RP-600-PCAR
GA-K8NS Ultra-939, Opteron 175, 1GB PNY Verto PC3500, 9600XT, CM Centurion 5/RS-450-ACLY
A7N8X-E Deluxe, XP-M 2600+ @218x11, 1GB KVR PC3200, 9550, Lian Li midtower/RS-450-ACLY
AN7, XP-M 2800+ @218x11, 1GB HyperX, AIW 9600XT, Antec Super LB/TPII Blue 480
http://classicplatforms.com Keeping "Old Tech" new.