X freezes with kvm and kernel-2.6.25-14.fc9.x86_64

[Slim Joe]

I'm running Fedora 9 under kvm. After a system update
involving the kernel-2.6.26.5-45.fc9.x86_64.rpm package,
Fedora freezes whenever I start to run X. The kvm screen
just goes black with the host computer's resources running
at 100% load.

I know it is an X-related problem because the screen freeze
doesn't happen if I run Fedora at runlevel 3 (by adding
"3" to the kernel line before grub boots). It's when I
type startx at the command prompt that the system locks
up. As root, I'm able to run and exit the SVGA version of
koules cleanly.

The freeze doesn't happen with the kernel installed by
kernel-2.6.25-14.fc9.x86_64.rpm (which is still available
as a grub boot option). Interestingly, however, the
Fedora splash screen (which suppresses the display of
the boot-up messages) appears to crash out. I can see
the boot-up messages on the console until the GDM log-in
screen appears.