Comment Drive geometry fixed if for me (Score 3, Informative) 608
It is interesting that BIOS updates fix that problem for most people. I recently installed FC2 and had exactly the same problem booting between it and XP. I was finally able to fix it by changing the drive geometry setting in my BIOS from Auto (which was using CHS) to LBA. As soon as I did that it started to boot XP again.