dbus rqmts for gnome-screensaver ?

[Rod Butcher <rbutcher hyenainternet com>]

I'm trying to run gnome-screensaver (cvs head version) and I get :-
(gnome-screensaver:5578): gnome-screensaver-WARNING **: couldn't connect
to session bus: Unable to determine the address of the message bus

(gnome-screensaver:5578): gnome-screensaver-WARNING **: failed to
register with the message bus

and the screensaver doesn't appear to run.

I believe I have both the system and session dbus-daemon running - using
the stock Mandrake rpms.
Can somebody give me a pointer to rqmts for running gnome-screensaver ?
I've read and digested the dbus documentation as far as I'm able, but
I'm not a developer. 
Does this mean that Gnome is switching from bonobo / corba to dbus ?
thanks
Rod