I have an onboard video (Intel HDMI) and Hitachi harddrive. I am going to install XP, and if the problem exists in XP, definitely it's MB issue
UPDATE: I got another SG33G5, fresh installed the Vista, and guess what?
? the HW interrupt is GONE, GONE, GONE!!!!!!!!
I am still using the shipped BIOS, not ready to upgrade yet. maybe it's how I upgrade the BIOS? Dunno... but it works!!!
UPDATE 2: Just updated BIOS and machine still works. It looks like the first SG33G5 that I got was a bad one.