Comment 2 for bug 724874

StacktraceTop:
 window_closed (screen=0x9023c10, win=0x915e800) at /build/buildd/compiz-0.9.4/unity/unity_window_decorator/src/wnck.c:722
 g_cclosure_marshal_VOID__OBJECT (closure=0x8ff2530, return_value=0x0, n_param_values=2, param_values=0x90bf790, invocation_hint=0xbfc4d7f0, marshal_data=0x0) at /build/buildd/glib2.0-2.28.1/./gobject/gmarshal.c:638
 g_closure_invoke (closure=0x8ff2530, return_value=0x0, n_param_values=2, param_values=0x90bf790, invocation_hint=0xbfc4d7f0) at /build/buildd/glib2.0-2.28.1/./gobject/gclosure.c:767
 signal_emit_unlocked_R (node=0x90228d8, detail=0, instance=0x9023c10, emission_return=0x0, instance_and_params=0x90bf790) at /build/buildd/glib2.0-2.28.1/./gobject/gsignal.c:3252
 g_signal_emit_valist (instance=0x9023c10, signal_id=150, detail=0, var_args=0xbfc4d9b0 "\364_u") at /build/buildd/glib2.0-2.28.1/./gobject/gsignal.c:2983