The latest libxcb in Fedora 8 is libxcb-1.0-4.fc8, whereas the latest version in the previous release, Fedora 7, already was libxcb-1.1 This prevents normal upgrade form (already EOF'ed) Fedora 7 to Fedora 8 (Note, that some people, especialy in production environments, do not prefer to upgrade to the Fedora 9, they prefer to upgrade to Fedora 8, as more stable distro. Please, do not promote the idea to use Fedora 9 instead of fixing this bug ;) )
libxcb-1.1-1.fc8 has been submitted as an update for Fedora 8
libxcb-1.1-1.fc8 has been pushed to the Fedora 8 testing repository. If problems still persist, please make note of it in this bug report. If you want to test the update, you can install it with su -c 'yum --enablerepo=updates-testing update libxcb'. You can provide feedback for this update here: http://admin.fedoraproject.org/updates/F8/FEDORA-2008-6609
1.1-1 reintroduces the locking issue at bug 390261 to F8. Perhaps the equivalent to fc9's 1.1-4 can be provided instead?
The latest locking issue has been fixed by 1.1-1.1 (cf. bug 456824) -- Thanks Adam