I have a dual-boot Fedora x86-64 / WinXP laptop, and the Fedora 13 upgrade failed soon after the 'upgrade' option was selected in the menu.
The problem was that the installer could not recognise the ...ntfs-3g.. entry for WinXP in /etc/fstab.
The fix is to (temporarily) change this entry to ...ntfs... and the install will then proceed OK.
May 25th, 2010
*** This bug has been marked as a duplicate of bug 577260 ***