Well, so far I've installed Vuescan and it appears to be working with my Epson 3200. (Just as well, since Epson don't seem to have a Vista 64 driver for it.) However, the Minolta isn't yet working with it, Vuescan just hangs - but at least the slide holder went in OK, so I'll try again.
I'm intrigued that you were able to load the Minolta software on Vista 64 and I'll probably give that a try, but only when I'm feeling really patient. (Vista 64 is driving me nuts too!)