On systems without PCI (like ps3), /sys/bus/pci is not created. The Xserver tries to accessed this file even if the driver is fbdev, which causes the server to crash. There is a fedora bug at https://bugzilla.redhat.com/show_bug.cgi?id=447593 which also describes the problem including backtrace.
fixed in fc9 (libpciaccess-no-pci-fix.patch)
... and also upstream - closing
Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.