40125W hangs at 75% burn

I have made loads of coasters with this burner.

It hangs XP for no reason , and i have to reset to get windows to
reboot. I have checked event viewer and nothing appears.

My setup is

Athlon 1 Ghz
Abit KT7 Raid motherboard
Sonic fury sound card
Radeon 64mb VIVO graphics
512 Meg ram

I know the VIA chipset is unstable but i usually do not have problems until XP professional is installed for a few weeks then everything goes hay wire ???

Anyone else got these problems ?

Any recently installed programs?
How is your drive connected?
Same problem in all writing programs?
Tried different types of media?