Can you clarify whether disk 0 is first in your BIOS boot sequence ?
You called it "the boot drive" but XP on drive 1 has the "system" flag, which means that's where all the Windows boot files are located.
Can you post screenshots of the partition root of each drive. (Make sure that folder options are set like this
so we can see everything)
My suspicion is that you've been booting with a non-bootable drive first in the BIOS and the boot has had to go to the second HDD each time.
When you instructed EasyBCD to rewrite the MBR/PBR, it would have done what you asked it to do, to the 1st HDD in the BIOS,
making it bootable but without an OS, hence the hang up. Because the first disk became bootable, it no longer had to skip to the second disk.
If I'm right, all you need to do is put the XP disk first in the BIOS, then do the uninstall Vista bootloader again. This time it will rewrite the MBR/PBR on the correct disk.