jokosher doesn't play clips imported with the freesound plugin

Running 0.10 on updated ubuntu 8.04:

Importing clip with freesound plugin only shows the visual waveform, but won't even start to play if play is pushed. Importing the same clip with the audio file importer works.

If there is any working clips already present, jokosher sometimes freezes, and must be killed, or just won't start playing.

output in terminal:

/usr/share/jokosher/extensions/FreesoundSearch-0.2-py2.4.egg/FreesoundSearch/FreesoundSearch.py:705: RuntimeWarning: tmpnam is a potential security risk to your program
  tmpnam = os.tmpnam()
/var/lib/python-support/python2.5/Jokosher/TransportManager.py:131: Warning: invalid unclassed pointer in cast to `GstMiniObject'
  self.pipeline.set_state(gst.STATE_READY)

(jokosher:23438): GStreamer-CRITICAL **: gst_mini_object_unref: assertion `mini_object->refcount > 0' failed