Problems in Firefox

[Mário Gamito]

Hi,

I've installed the current stable Kubuntu, but i cannot run Firefox as a 
regular user, only with sudo.

I tried with Kubuntu package as well as with the downloadable version 
and the result is the same.

The error i get is:
------------------------------------------------
(Gecko:9730): GLib-GObject-WARNING **: invalid uninstantiatable type 
`(null)' in cast to `GtkWidget'

(Gecko:9730): GLib-GObject-WARNING **: invalid uninstantiatable type 
`(null)' in cast to `GObject'

(Gecko:9730): GLib-GObject-CRITICAL **: g_object_get_data: assertion 
`G_IS_OBJECT (object)' failed
/usr/local/firefox/run-mozilla.sh: line 131:  9730 Segmentation fault 
"$prog" ${1+"$@"}
-------------------------------------------------

Any help would be appreciated.

Warm regards
-- 
:wq! Mário Gamito