The format of /proc/partitions has changed, so that instead of getting a line like: 3 1 48163 hda1 you will find a line like: 3 1 4000 ide/host0/bus0/target0/lun0/part1 and it doesn't like it. (The above 2 lines are from different machines, but show the format change.) The workaround is to change the entries in /etc/fstab.
You're using devfs. This makes a very large difference - without devfs, the names are the same.
Does it work with e2fsprogs-1.20-0.02 or higher from rawhide? I have also uploaded that version to http://people.redhat.com/laroche/
Should work with newer e2fsprogs tools, otherwise please open a new bug-report. Thanks, Florian La Roche