I just performed an upgrade from Fedora 8 to Fedora 9 using preupgrade. I had this version of grub installed: grub-0.97-33.1.fc8.i386 yum did not upgrade this rpm to the Fedora 9 version, because the pushed F9 version is older than the F8 version: grub-0.97-33.fc9.i386.rpm It seems that the F8 version went from 33.fc8 to 33.1.fc8, which is newer than F9's 33.fc9. F8's version should have been built as 33.fc8.1 instead. To solve this, F9's grub should be rebuilt as 34.fc9 and pushed.
Hmm. That said, this won't help fix preupgrade, or the upgrade-via-F9-release-cd path, since they both use the initial F9 release RPMs that can't be changed. Can grub in F9 be down-graded to and older name-version-release? I guess that's not possible for people who've already 'yum update'd... Shouldn't Koji/Bodhi enforce the NVR ordering between releases? For some reason, I thought it did...
*** This bug has been marked as a duplicate of bug 469486 ***