Description of Problem:
mozilla exits abnormally with the following diagnostics:

Gtk-WARNING **: invalid class type `(unknown)' in cast to `GtkObject'
Gtk-CRITICAL **: file gtkobject.c: line 1101 (gtk_object_remove_data):
assertion `GTK_IS_OBJECT (object)' failed.
Gtk-WARNING **: invalid class type `(unknown)' in cast to `GtkObject'
Gtk-CRITICAL **: file gtkobject.c: line 1101 (gtk_object_remove_data):
assertion `GTK_IS_OBJECT (object)' failed.
Gtk-WARNING **: invalid class type `(unknown)' in cast to `GtkObject'
Gtk-CRITICAL **: file gtkobject.c: line 1101 (gtk_object_remove_data):
assertion `GTK_IS_OBJECT (object)' failed.

It typically does this after hitting "reload" after being idle for some
time (like 1-15 minutes or so).

Version-Release number of selected component (if applicable):

kdebindings-kmozilla-2.2-2
mozilla-mail-0.9.2-10
mozilla-psm-0.9.2-10
mozilla-chat-0.9.2-10
nautilus-mozilla-1.0.4-34
mozilla-0.9.2-10
mozilla-devel-0.9.2-10

How Reproducible:
can't seem to force it reliably, but seems to be about 80%

Steps to Reproduce:
1. start mozilla (from an xterm)
2. let it idle for 10-15 minutes
3. hit "reload"

Actual Results:
abnormal termination

Expected Results:
a reloaded page

Additional Information: