I tried 188.8.131.52-17 fedora build and found no patch for http://bugs.freedesktop.org/show_bug.cgi?id=14507.
I tried git version 184.108.40.206 and it fixed!
The bug must be in our modesetting patches then.
i tried booth kernel-220.127.116.11-19.fc9 fedora build and 18.104.22.168 git version.
Same issue, fedora build do not have fix, and git version works fine. I use same .config for booth kernels (make xconfig/load "/boog/config-...19")
Look like here some bad patch in fedora build
Works fine under Fedora 10