Good question. Aperture has changed a bit in the last 3 years. I would "update Vault" but now I get that question I had in my previous post. "Do you want to replace contents of Vault with Library". I'm guessing it's the Library on my StartUp HD where Aperture app. is. So ike i said my main library has 4 more GB's than my vault and when I try to update it, it says it's already up to date. But then you have these otheor option like restore library, update vault path. So I'm confused.