I could not see it on the download page.
There is no special version of 64bit Vista, the installer is the same for all OSes. So, on the usual download page - here.
The installer only uses the 32bit ashdisp.exe. It does not use the 64 bit version.
It still works with 64bit OS though, there are many XP64 and Vista64 users on the forums and they downloaded the standard installation file.
That’s how it’s supposed to be.
What is the problem?