Hope fix a gstreamer bug: https://code.google.com/p/quodlibet/source/diff?spec=svn1dcd91afd25144400f7f0172bc467ca87d9a1cd9&name=1dcd91afd251&r=1dcd91afd25144400f7f0172bc467ca87d9a1cd9&format=side&path=/quodlibet/quodlibet/player/gstbe.py