Operating system: 11.2 (2.6.31.8-0.1-desktop #1 SMP PREEMPT 2009-12-15 23:55:40 +0100 x86_64 x86_64 x86_64 GNU/Linux)
Machine: Dell Latitude 630
Install: Clean (i.e. not upgraded)
Window manager: GNOME 2.28

At least once a day (sometimes twice), GNOME crashes. I see the following in .xession-errors:

(gnome-settings-daemon:12834): GLib-GObject-CRITICAL **: g_param_spec_flags: assertion `G_TYPE_IS_FLAGS (flags_type)' failed

(gnome-settings-daemon:12834): GLib-GObject-CRITICAL **: g_object_class_install_property: assertion `G_IS_PARAM_SPEC (pspec)' failed
*** nss-shared-helper: Shared database disabled (set NSS_USE_SHARED_DB to enable).
*** nss-shared-helper: Shared database disabled (set NSS_USE_SHARED_DB to enable).
Window manager warning: Buggy client sent a _NET_ACTIVE_WINDOW message with a timestamp of 0 for 0x2c00037 (Mozilla Fi)
Window manager warning: meta_window_activate called by a pager with a 0 timestamp; the pager needs to be fixed.

Has anyone else ever seen this?

Thanks,
Rick