Comment 8 for bug 868868

And the same stack from valgrind:

==10980== Process terminating with default action of signal 11 (SIGSEGV)
==10980== General Protection Fault
==10980== at 0x18CC0A3D: unity::PanelTray::FilterTrayCallback(_NaTray*, _NaTrayChild*, unity::PanelTray*) (PanelTray.cpp:160)
==10980== by 0x1A5BD061: ??? (in /usr/lib/libunity-misc.so.4.1.0)
==10980== by 0x9A810A3: g_closure_invoke (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.3000.0)
==10980== by 0x9A93029: ??? (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.3000.0)
==10980== by 0x9A9C6B0: g_signal_emit_valist (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.3000.0)
==10980== by 0x9A9C851: g_signal_emit (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.3000.0)
==10980== by 0x1A5BBCCE: ??? (in /usr/lib/libunity-misc.so.4.1.0)
==10980== by 0x8135250: ??? (in /usr/lib/libgdk-3.so.0.200.0)
==10980== by 0x81353CE: ??? (in /usr/lib/libgdk-3.so.0.200.0)
==10980== by 0x810D720: gdk_display_get_event (in /usr/lib/libgdk-3.so.0.200.0)
==10980== by 0x81350F1: ??? (in /usr/lib/libgdk-3.so.0.200.0)
==10980== by 0x66A6A5C: g_main_context_dispatch (in /lib/x86_64-linux-gnu/libglib-2.0.so.0.3000.0)
==10980==