You need to file a bug on the package. It shouldn't be sitting in I/O wait states or other things when you click logout.

On Mon, Mar 15, 2010 at 1:04 PM, James Heather <j.heather@surrey.ac.uk> wrote:
An update on this: it is xorg-x11-drv-synaptics causing the bother.

To verify this, you can build a live cd from the F11 release repo, without enabling updates. Put it on a USB stick, boot off it, and you can log in and out with no trouble. Then

    yum update xorg-x11-drv-synaptics