FC4 - laptop can no longer shutdown

[Ben Stringer]

I have a Dell Inspiron 8600 laptop, that has recently stopped being able
to shut down. It seems to have occurred since a yum upgrade I performed
on March 31, which included kernel 2.6.16-1.2069_FC4, glibc 2.3.6-2 and
selinux-policy-targeted 1.27.1-2.28.

The symptom is that when running the shutdown command (either via gnome
or the command line), no processes are terminated, nothing is logged
in /var/log/syslog or dmesg. An strace shows shutdown waiting on a
futex.

I have tried (one at a time) the previous kernel (2.6.15-1.1831_FC4),
tried disabling SELinux, and tried manually killing individual processes
until I'm just left with the shell I am running, mingetty, and kernel
procs. Still can't shutdown.

My grub kernel line is:

  kernel /boot/vmlinuz-2.6.16-1.2069_FC4 ro root=LABEL=/ rhgb quiet

Any advice (or similar experiences) appreciated. 

Cheers, Ben