Hi there
Build 6000 doesn't seem to be a release version of Vista. You'll need a legitimate copy of a release version of Vista. For example, Vista Business, Home Basic, Ultimate etc.
That is certainly a fair question - unfortunately I can't give you a good answer. I can say that we encourage people to keep their machines up-to-date with the latest service packs and fixes, and that policy *may* be the reason why Vista SP2 is required. In the long run it would be better if you could get more RAM...Sure it is not helping, but may I ask, why exactly MP requires SP2 of Vista? Are there some breaking things that exist in XP, Vista SP2 and 7, but not in Vista SP1? Just asking