Install Vista first then Ubuntu, Grub should handle it then. It may freak
out the Windows bootloader and give error 0xc0000001 but booting from the
Windows install DVD, hit the link for System Restore on the install welcome
page should restore startup. This may not happen if you install Linux on a
different physical drive but I haven't tried this yet so just being
optimistic. I haven't tried BootMagic or other 3rd party with Vista and am
a little nervous about trying so that can be your experiment.