Description of problem: running preupgrade (f8 to f10) has been a chore. here are the things i've had to tweak... 1. hang at boot time on nvidia 6800 card, so edit grub.conf to boot in text mode. I *STRONGLY* recommend this for all preupgrade-based upgrades because it's mostly unattended at boot time. 2. preupgrade mounted the wrong partition to upgrade... i have several potential root partitions on my disk. sda1,2,6 and they have variably-old fedora installs. sda1 was "active" and also first, but I'd been using sda2 as the root partition with grub installed to the MBR and (hd0,1) as the boot partition. for some reason, /dev/sda1 was mounted as /mnt/sysimage instead of sda2. I moved all the files in that partition to a subdirectory so it didn't look like a fedora install and set sda2 to be the only active/bootable partition and that fixed the problem.
I'm guessing you've got multiple Fedora installations on your machine. Anaconda in F10 does not have a way to specify *which* filesystem to upgrade in a kickstart, so it just chooses the first one it finds. Remove 'upgrade' from /boot/upgrade/ks.cfg and it will prompt you to choose which one to upgrade. Future versions of preupgrade/anaconda will use an 'upgrade --root=XXX' command to pick the correct root filesystem, rather than just using the first one it finds. *** This bug has been marked as a duplicate of bug 471232 ***