I recently purchased a Zune (whilst in the US) and I had some problems trying to get it working on my x64 version of Vista. I initially found problems with the software bundled with the Zune and read lots of issues with it working on Vista x64. I managed to solve all these (after playing around with all this hacking of the existing msi etc.) by downloaded the latest version of the Zune software (http://www.zune.net/en-us/meetzune/software.htm)
This seemed to install ok but then reported a issue I rebooted and tried again the installation was successful. Once the software was installed it began to update the firmware on the Zune. I have not had a problem with it so far. As I am in the UK I am aware that the marketplace does not work.
Ravi Nar
"Somebody give me the baton I wanna run!"