Instance of invalid non-instantiable type <unknown>?

[William Page <compenguy gmail com>]

When my program terminates, I get these three errors repeated about 5 times. 
I can't figure out what's causing it.

(lc3sim:32683): GLib-GObject-WARNING **: instance of invalid 
non-instantiatable type `<unknown>'

(lc3sim:32683): GLib-GObject-CRITICAL **: 
g_signal_handlers_disconnect_matched: assertion `G_TYPE_CHECK_INSTANCE 
(instance)' failed

(lc3sim:32683): Gtk-CRITICAL **: gtk_accel_group_disconnect: assertion 
`GTK_IS_ACCEL_GROUP (accel_group)' failed


William Page