(gdb) bt
#0  0xac6f486e in ?? () from /usr/lib/firefox/extensions/globalmenu@ubuntu.com/components/libglobalmenu.so
#1  0xac6f4eda in ?? () from /usr/lib/firefox/extensions/globalmenu@ubuntu.com/components/libglobalmenu.so
#2  0xac6f5713 in ?? () from /usr/lib/firefox/extensions/globalmenu@ubuntu.com/components/libglobalmenu.so
#3  0xb310faf0 in ?? () from /usr/lib/i386-linux-gnu/libdbusmenu-glib.so.4
#4  0xb5851484 in g_closure_invoke () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#5  0xb58630d9 in ?? () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#6  0xb586aff5 in g_signal_emit_valist () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#7  0xb586b453 in g_signal_emit () from /usr/lib/i386-linux-gnu/libgobject-2.0.so.0
#8  0xb310f4d6 in dbusmenu_menuitem_handle_event () from /usr/lib/i386-linux-gnu/libdbusmenu-glib.so.4
#9  0xb3110de3 in ?? () from /usr/lib/i386-linux-gnu/libdbusmenu-glib.so.4
#10 0xb5792a7f in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#11 0xb5791d86 in g_main_context_dispatch () from /lib/i386-linux-gnu/libglib-2.0.so.0
#12 0xb5792125 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#13 0xb5792201 in g_main_context_iteration () from /lib/i386-linux-gnu/libglib-2.0.so.0
#14 0xb673a670 in ?? () from /usr/lib/firefox/libxul.so
#15 0xb67543b9 in ?? () from /usr/lib/firefox/libxul.so
#16 0xb67544a4 in ?? () from /usr/lib/firefox/libxul.so
#17 0xb68f0233 in ?? () from /usr/lib/firefox/libxul.so
#18 0xb68bed23 in ?? () from /usr/lib/firefox/libxul.so
#19 0xb680a158 in ?? () from /usr/lib/firefox/libxul.so
#20 0xb691411a in ?? () from /usr/lib/firefox/libxul.so
#21 0xb6914242 in ?? () from /usr/lib/firefox/libxul.so
#22 0xb6753ca0 in ?? () from /usr/lib/firefox/libxul.so
#23 0xb66020ab in ?? () from /usr/lib/firefox/libxul.so
#24 0xb5d46129 in ?? () from /usr/lib/firefox/libxul.so
#25 0xb5d46355 in ?? () from /usr/lib/firefox/libxul.so
#26 0xb5d4659a in XRE_main () from /usr/lib/firefox/libxul.so
#27 0x80001f2c in ?? ()
#28 0xb7cea4d3 in __libc_start_main () from /lib/i386-linux-gnu/libc.so.6
#29 0x80001f95 in _start ()