Vista - Dual-boot trouble

I'm running XP Pro on my primary hard drive. Yesterday I installed 64-bit
Vista on my secondary hard drive. I expected to be able to dual boot, but not
so: I lost the ability to boot into XP after installing Vista. No OS menu was
displayed during the boot process. XP was not even listed as a startup option
in Vista.

I tried running bootcfg /rebuild in the XP repair console, but it wouldn't
run (ever after running chkdisk). Then I used bcdedit to make the boot menu
appear. I set {legacy} as the default OS. This caused the OS menu to appear
during the boot process. However, I still wasn't able to boot XP because
ntldr was corrupted.

I finally managed to restore XP by playing around with the XP repair console
but, to be honest, I'm not sure how I did it, and in the process I lost the
ability to boot Vista.

Is this expected behavior? I have an AMD Athlon x2 3800+, an nForce 4 Ultra
chipset, two SATA hard drives and a PATA DVD burner.