Youtube applet crash when screen is not composited

Debian Lenny with metacity, without composite manager enable. Youtube applet (and maybe other) crash on startup :
Traceback (most recent call last):
  File "/usr/share/screenlets/Youtube/YoutubeScreenlet.py", line 324, in <module>
    screenlets.session.create_session(YoutubeScreenlet)
  File "/usr/lib/python2.5/site-packages/screenlets/session.py", line 351, in create_session
    session.start()
  File "/usr/lib/python2.5/site-packages/screenlets/session.py", line 197, in start
    sl = self.create_instance()
  File "/usr/lib/python2.5/site-packages/screenlets/session.py", line 130, in create_instance
    sl.finish_loading()
  File "/usr/lib/python2.5/site-packages/screenlets/screenlet.py", line 380, in finish_loading
    self.update_shape()
  File "/usr/lib/python2.5/site-packages/screenlets/screenlet.py", line 555, in update_shape
    if self.window.is_composited() or (self.window.plug is not None
AttributeError: 'gtk.Layout' object has no attribute 'plug'