yes NOD32 is compatable with 64bit Vista, although not the latest release, V3 has issues with outlook, they are aware of it and just tell you to use 2.8, their support said that 2.8 is just as safe and basically the same as 3 but without the nice front end.
Either way I reported this to them when V3 came out and they still havent fixed it, my license runs out in 4 days!, and to be honest I think im going to go to AVAST, iv been using that on my works laptop (Vista 64bit) for quite a few months now and I havent had an issue. Just dont like idea of paying for the latest version but not being able to use it.