I skipped kernel-2.6.17-1.2139_FC5 because of the many reported problems. Today,
I decided to upgrade to kernel-2.6.17-1.2145_FC5 with "yum update". However,
after a restart, I got the following error messages:

INIT: version 2.86 booting
INIT: No inittab file found

After that you're stuck. Happens with any of the remaining kernels:

kernel-2.6.16-1.2133_FC5
kernel-2.6.17-1.2145_FC5

From /var/log/yum.log:

Jul 08 13:43:57 Erased: initscripts
Jul 08 13:44:21 Installed: kernel.i686 2.6.17-1.2145_FC5
Jul 08 13:44:23 Updated: gnupg.i386 1.4.4-2.2
Jul 08 13:44:23 Updated: xorg-x11-drv-ati.i386 6.5.8.0-1
Jul 08 13:44:40 Installed: kernel-devel.i686 2.6.17-1.2145_FC5
Jul 08 13:44:42 Updated: initscripts.i386 8.31.5-1
Jul 08 13:44:43 Updated: evolution-sharp.i386 0.10.2-9.5

It appears that the upgrade of the initscripts package didn't finish properly
(just a guess) as there was a file inittab.rpmsave in /etc but no inittab
anymore. Restarting with the Fedora rescue CD and subsequently copying
/etc/inittab.rpmsave to /etc/inittab worked fine though and allowed me to
properly restart the computer.

Situations like this are fatal for non-technical people and actually very scary
as it isn't obvious what steps to perform after starting from the Fedora rescue CD.