Comment 18 for bug 502673

It's actually blocking in X waiting on more events, so not sure if Gtk+ would be at fault. Can someone try to comment out gdk_flush in linux/wulformanager.cc to see if it resolves it for them? Another alternative is to call X directly using XFlush() since the XSync() in gdk_flush() is a more expensive round-trip operation that is not necessary for our purposes (kind of nasty though).

#include <gdk/gdkx.h>

XFlush(GDK_DISPLAY_XDISPLAY(gdk_display_get_default());