I tried this on Arch linux x64, surf-hg. It did not segfault, but produced these warnings on each border click:
(<unknown>:31278): Gdk-CRITICAL **: gdk_window_get_events: assertion `GDK_IS_WINDOW (window)' failed (<unknown>:31278): GLib-GObject-CRITICAL **: g_object_ref: assertion `G_IS_OBJECT (object)' failed (<unknown>:31278): GLib-GObject-CRITICAL **: g_object_unref: assertion `G_IS_OBJECT (object)' failed I have also seen such warnings with a GTK app I wrote when its border was clicked. I was not able to find any related information.