Aborting a threaded load raises exception

[anonymous]

When loading a file using background threaded loading, trying to kill the load by closing the buffer results in:

Traceback (most recent call last):
  File "/usr/lib64/python2.5/site-packages/wx-2.8-gtk2-unicode/wx/_core.py", line 14551, in <lambda>
    lambda event: event.callable(*event.args, **event.kw) )
  File "/home/rob/src/peppy-git/peppy/mainmenu.py", line 417, in action
    self.frame.closeBuffer()
  File "/home/rob/src/peppy-git/peppy/frame.py", line 648, in closeBuffer
    if buffer.numViewers() > 1:
AttributeError: 'LoadingBuffer' object has no attribute 'numViewers'