AttributeError: ' ' object has no attribute ' '

[matt.doolittle33 at gmail.com]

I am using Ubuntu 12.10, and Python 2.7.3, GNU Radio Companion v3.6.3.  I get the this error in terminal: 

 in __init__
    self.wxgui_waterfallsink2_0.set_callback(wxgui_waterfallsink2_0_callback)
  File "/usr/local/lib/python2.7/dist-packages/gnuradio/gr/hier_block2.py", line 54, in __getattr__
    return getattr(self._hb, name)
AttributeError: 'gr_hier_block2_sptr' object has no attribute 'set_callback'

I have been getting this error in multiple programs.  So what is stopping the program here?  There is no Attribute .set_callback obviously. But where is this attribute missing from exactly and how do i put it where it should be?