Bug#267431: crashes on adding new printer

[Michael P]

I get a crash, too.  Here's the output on the terminal when I run
  'gksu gnome-cups-add'

p@m:~$ gksu gnome-cups-add

(gnome-cups-add:7464): GnomeUI-WARNING **: While connecting to session
manager: Authentication Rejected, reason : None of the authentication
protocols specified are supported and host-based authentication failed.

** (gnome-cups-add:7464): CRITICAL **: file gnome-cups-printer.c: line 775
(gnome_cups_printer_get_attributes_initialized): assertion
`GNOME_CUPS_IS_PRINTER (printer)' failed

** (gnome-cups-add:7464): CRITICAL **: file gnome-cups-request.c: line 410
(gnome_cups_request_new_for_printer): assertion
`gnome_cups_printer_get_attributes_initialized (printer)' failed