Vista boot fails after XP install

Hi,

I used this <a href="http://apcmag.com/5485/dualbooting_vista_and_xp
guide">article</a> to add an XP installation next to an existing Vista
installation, with the difference that I used a second hard disk for
XP.

This is what I did:
- Add second hard disk as slave and boot Vista. Vista boots (from
primary) and recognizes the second hard disk and I can browse the
files on it.
- Boot with XP cd-rom and install XP on the second hard disk (which it
calls D. The XP installation copies its files and reboots. Then I
get a boot error.
- Boot with Vista cd-rom and repair the MBR. Vista recognizes the
(one) Vista installation, I choose to repair the MBR and it reports
that it found an error and fixed it.
- Reboot Vista -> boot error!

And there I get the standard boot error message at the command prompt.
I disconnected the second hard disk (with half-way XP install) and set
the DVD player on that cable back to primary. Still the same error.

Now I can only boot with the Vista cd-rom. It still finds the (one)
Vista install, when I try to repair it it reports there was nothing to
repair. But still I can't boot it...

Any help is greatly appreciated.

Regards,

- John