I found out that bonobo had "forgotten" it's settings. This fixed it:
$ sudo bonobo-activation-sysconf --add-directory=/usr/lib/bonobo/servers -- Bonobo broken on PowerPC Edgy RC https://launchpad.net/bugs/67465 -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
