I had a similar issue, what seems to fix it for me is:
rpm -Uvh --oldpackage ./dbus-1.0.0-6.el5.x86_64.rpm
rpm -Uvh --oldpackage ./dbus-devel-1.0.0-6.el5.x86_64.rpm
rpm -Uvh --oldpackage ./dbus-x11-1.0.0-6.el5.x86_64.rpm
where the rpms are off of CentOS 5.1 (64-bit) CD-ROMS
which will "rollback" dbus (there was a recent update)
see
http://www.linuxcompatible.org/CESA-...e_s107406.html
hope this helps, now I am off to tell ``yum update'' not to touch dbus