You just can’t pilfer parts of other OSen whenever you feel like it. If you take certutil.exe from a newer OS than XP (eg – Vista, Server 2003, Server 2008) then it’s not gonna’ work. What, you don’t believe me, check it out ya’ silly cannigut:
http://support.microsoft.com/kb/934576/en-us?spid=12925&sid=1569
But I’d really hoped you knew to look this kind of thing up already if you’re doing work on PKI stuff… 😉