Mail Notification error on startup

[Andrew Robinson]

Almost every time I log into xfce I get an error in mail notification:

A fatal error has occurred in Mail Notification
A Bonobo exception (Unknown CORBA exception id:
'IDL:omg.org/CORBA/COMM_FAILURE:1.0') has occurred in
GNOME:MailNotification:Automation:hasMailboxes().

If I open the configuration from xfce settings, it re-starts fine.

Any ideas on why this happens on start of xfce?

-Andrew