Valgrind invalid write warning

Using current trusty, got that while running usd under valgrind

==17415== Invalid write of size 4
==17415== at 0x4851F3F: g_variant_valist_get (gvariant.c:4943)
==17415== by 0x4851DB4: g_variant_valist_get (gvariant.c:5127)
==17415== by 0x4852A6C: g_variant_get_va (gvariant.c:5354)
==17415== by 0x4852CAB: g_variant_get (gvariant.c:5301)
==17415== by 0xA9EB18C: shell_key_grabber_call_grab_accelerator_finish (shell-key-grabber.c:610)
==17415== by 0xA9E498B: grab_accelerator_complete (gsd-media-keys-manager.c:718)
==17415== by 0x46680A4: g_simple_async_result_complete (gsimpleasyncresult.c:763)
==17415== by 0x46D7FAC: reply_cb (gdbusproxy.c:2623)
==17415== by 0x46680A4: g_simple_async_result_complete (gsimpleasyncresult.c:763)
==17415== by 0x46CC7A7: g_dbus_connection_call_done (gdbusconnection.c:5498)
==17415== by 0x46680A4: g_simple_async_result_complete (gsimpleasyncresult.c:763)
==17415== by 0x466810A: complete_in_idle_cb (gsimpleasyncresult.c:775)
==17415== by 0x4814C4F: g_idle_dispatch (gmain.c:5319)
==17415== by 0x48180A6: g_main_context_dispatch (gmain.c:3064)
==17415== by 0x4818467: g_main_context_iterate.isra.24 (gmain.c:3734)
==17415== by 0x481876A: g_main_loop_run (gmain.c:3928)
==17415== by 0x425334C: gtk_main (gtkmain.c:1158)
==17415== by 0x804AA29: main (main.c:476)
==17415== Address 0x8b22c5c is 28 bytes inside a block of size 32 free'd
==17415== at 0x402AD58: free (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==17415== by 0x481DD2F: g_free (gmem.c:190)
==17415== by 0xA9E49F4: media_key_free (gsd-media-keys-manager.c:397)
==17415== by 0x47EAFB9: g_ptr_array_remove_index_fast (garray.c:1227)
==17415== by 0xA9E648F: update_custom_binding (gsd-media-keys-manager.c:910)
==17415== by 0xA9E6712: custom_binding_changed (gsd-media-keys-manager.c:936)
==17415== by 0x478F320: g_cclosure_marshal_VOID__STRINGv (gmarshal.c:1004)
==17415== by 0x478CCCD: _g_closure_invoke_va (gclosure.c:831)
==17415== by 0x47A607F: g_signal_emit_valist (gsignal.c:3215)
==17415== by 0x47A6BF2: g_signal_emit (gsignal.c:3363)
==17415== by 0x46B781F: g_settings_real_change_event (gsettings.c:277)
==17415== by 0x4FD63C5: ffi_call_SYSV (sysv.S:65)
==17415== by 0x4FD614A: ffi_call (ffi.c:411)
==17415== by 0x478D670: g_cclosure_marshal_generic_va (gclosure.c:1541)
==17415== by 0x478B456: g_type_class_meta_marshalv (gclosure.c:988)
==17415== by 0x478CCCD: _g_closure_invoke_va (gclosure.c:831)
==17415== by 0x47A607F: g_signal_emit_valist (gsignal.c:3215)
==17415== by 0x47A6BF2: g_signal_emit (gsignal.c:3363)
==17415== by 0x46B813F: settings_backend_path_changed (gsettings.c:352)
==17415== by 0x46B2407: g_settings_backend_invoke_closure (gsettingsbackend.c:267)
==17415== by 0x4814C4F: g_idle_dispatch (gmain.c:5319)
==17415== by 0x48180A6: g_main_context_dispatch (gmain.c:3064)
==17415== by 0x4818467: g_main_context_iterate.isra.24 (gmain.c:3734)
==17415== by 0x481876A: g_main_loop_run (gmain.c:3928)
==17415== by 0x425334C: gtk_main (gtkmain.c:1158)
==17415== by 0x804AA29: main (main.c:476)