I'm happy that VISTA 64 is working for you - for me on my Studio 1535 - I have slow, intermittant internet connections on wireless and direct connect to cable broadband, simple games like Spider Solitaire continually blue screen, and too much of the open source code available on the internet doesn't work with VISTA 64 - not too mention the limited hardware certified by Microsoft.
I've spent five months fighting VISTA 64 and then downgrading to XP. I don't know if it's DELL or Microsoft - I don't care. I don't care if the support for hardware goes away, I don't care if the support for software goes away, I just want my sister-in-law's Christmas present to work. XP does, VISTA 64 does not