This usually occur when 2 drives (not partitioned, but 2 physical HDD) are set ACTIVE. I encountered this problem several times, and several times I tweak BIOS setup, do some calculation,
Solution 1
install vista into one HDD only. If you partitioned it, make sure the OS will be installed on the first partition (the topmost, Drive C).
Solution 2
If you have two or more physical HDDs, unplug the those HDDs and do Solution 1. After successfully installed Vista, shut it down, then plug the unplugged HDDs.
25 computers in our office are now running Vista Enterprise. Some of those have SATA, mixed with IDE, SCSI, 2 or more HDDs, various partions, etc.. I just did what I advice here, and all of those work just fine.
I don't think MS is to be blamed here, I went thru this problem and happily got out. Well, in some cases this prob is some kind of bug because the partition tool in Vista Setup isn't complex enough to handle this kind of situation... You couldn't even activate and deactivate partition unlike FDISK in DOS environment...