Well, I don't know if it's related or not, but since the previous version of Catalyst (prior to 7.3 then), I get strange BSOD appearing once in a while and I didn't notice any particular pattern: just a totally empty BSOD... a manual reset (ctrl+alt+del doesn't work at all) is the only solution to reboot the pc.
I guess it's a driver issue because I have not a single problem under XP Pro I have on another drive, but I'm not sure.
BTW, I have an aX850 XT (AGP).
The update went fine without errors for Catalyst 7.3, but again the empty BSOD didn't appear especially because of Catalyst 7.3.