Please see the referenced Red Hat bug for details.
References to external bugzillas are useful, but details should be supplied
directly in the X.Org reports directly. Current CVS has feature to disable
extensions via new config file syntax, as you've requested in the RH
I'm closing this as FIXED for now. If the hang problem still exists in
current X.Org CVS code, which is in Fedora devel also (188.8.131.523), please
feel free to reopen the report here, but including all details here in
freedesktop bugzilla to make it easier on whoever investigates the issue.
Thanks in advance.