I appear to have the same problem as the original poster - I'll give a bit more info.
I had a single hard drive, with XP installed on a primary partition C: and a separate logical drive D: on an extended partition.
I added a second internal HDD, created an NTFS partition on it, and installed Vista through XP to the NTFS partition (H:, according to XP) on the second hard drive.
Everything worked fine, with the Vista boot menu allowing me to choose Vista (default) or XP, with the three second default. I wanted to change to XP as the default, and rename the OSes, so I installed Vista Boot Pro 2 on XP.
Renamed the OSes, changed the default timeout to 10 seconds, XP was identified as C:, while Vista was identified as H:, and applied the changes and rebooted.
After trying to choose XP on the boot menu, it comes up with the unable to find ntldr message. I was able to regain access to XP using XP Recovery Console and fixboot, and then rebooted into XP and tried "Reinstall the Vista Bootloader" from BootPro, which was successful. OSes are still correctly identified as C: and H: for XP and Vista (respectively), but after rebooting, I still get the ntldr error when trying to start XP.
Suggestions?
split to new thread by gries818


