Vista Still Having Problems with Server 2003 Admin Pack
Michael over at 4sysops has a follow-on post about the problems Vista users are having with the Windows Server 2003 Admin Pack. There is a known work-around to making it install properly on Vista. Also, released today by Microsoft is a compatibility update that fixes some, but not all problems with the Admin Pack.
Check out Michael's post at: http://4sysops.com/archives/vista-compatibility-update-for-the-adminpak
Also, check out his previous post with the workaround at: http://4sysops.com/archives/install-windows-server-2003-adminpak-administration-tools-pack-on-vista