Don't give up yet. I had to go to bed which is why I asked for the others to help.
Have you tried to switch to a different drive under Manage OS Entries for XP?
Have you Forced installation of the Vista bootloader after doing the above and after moving those files?
These two problems can cause that same issue to keep reappearing if you didn't do them. Also, if it comes down to it, just pop in the Vista DVD and select "Startup Repair" at the installation screen which can detect and repair issues that VBP does not have the ability to do.
Sometimes the BCD Registry is more messed up than what we can see on the surface.
We will get it worked out though. Just be patient.