Does Vegas 6 work with Vista?

Vegas 6 will "function" under Vista, but is not supported in any way by Sony. Use Vegas under Vista at your own risk.

Does Vegas 7 "function" any better under Vista than Vegas 6?

No. Vegas currently is not supporting Vista. If you don't have your machine/OS already, for most multi-media apps, it's a good idea to avoid Vista, IMO.
Microsoft has XPPro back in the boxes on the store shelves, because Vista isn't really ready for primetime just yet.

Vista will be the "New Coke" of software, nobody likes it, nobody wants it, and ultimately they will drop it in favor of XP Classic... mark my words. While Vista is selling 'well' as microsoft will say, the computer manufacturers aren't happy with it. Microsoft admitted to selling twice as many copies of XP this year as they had anticipated (as they were planning to phase it out.)

Vista will be the "New Coke" of software, nobody likes it, nobody wants it, and ultimately they will drop it in favor of XP Classic... mark my words.

We can only hope...................I swear they made VISTA because Bill Gates was jealous of that cartoon menu from APPLE.