Multimedia keys [1] did not work on RHEL 5, which was missing the keymap quirk [2] patch written by rhughes. Backporting was fun while it lasted—now my life feels hollower than ever.
[1] https://bugzilla.redhat.com/show_bug.cgi?id=450326
[2] http://people.freedesktop.org/~hughsient/quirk/quirk-keymap-index.html