xp-pro / vista dual boot problem

Okay, I have xp-pro on my primary partition and I had Vista-Beta on my
secondary. Was able to dual boot without any problems for 3 months. Now I
have upgraded Vista-Beta to the new Vista-RC1 and I can boot into Vista-RC1
without any problems, but it will no longer let me boot into XP-Pro.
Whenever I choose the Earlier Version of Windows from the dual boot menu, it
gives me a message that my Earlier Version installation is corrupt and that I
need to re-install the operating system. So, I put my XP disc in, went to
the repair console and did a FIXBOOT. Now I can boot fine into XP-Pro, but
it doesn't even give me the dual boot screen, so now I can't get into
Vista-RC1

Anyone else run into this problem. Any suggestions about how to fix it?

Thanks,

Bryan