10A380 might update but that is a pirated build (unless you are a developer, but then you would have the 10.6 GM anyway) So why don't you go to the Apple Store and pickup the 10.6 DVD. Its $30 and will update to 10.6.3 just dandy. Oh p.s. you DON'T want to be running 10D538, that is a pre-releae build as well and pretty buggy yet.