Trying to install FC5T3 on my Vaio SZ140 (very newish laptop from Sony). The install went fine, but upon reboot, the machine hangs a few seconds after the 'Starting udev' message.
Put "set -x" at the beginning of /sbin/start_udev [use a rescue mode CD-ROM]; boot and see where it hangs. Later in the same script, trace the system calls of /sbin/udevstart: "strace /sbin/udevstart".
I have different hardware with the same symptom. The cause seems to be related to USB probing, and began somewhere around kernel-2.6.15: https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=179601 I am nearing the end of a "git bisect" search to find the kernel bug.