A recent X server update broke the Geode driver, which is used on the OLPC. The fix is in the Geode driver, and has been built here:

http://koji.fedoraproject.org/koji/buildinfo?buildID=101853

Without the fix, X crashes immediately at startup. (So this can't go out as an update.)

I'm the upstream maintainer of the geode driver, and have tested the new RPM myself. There's no risk to anything other than the geode driver.

Thanks!