Client throws intermittent "Exception in thread dispatcher-thread" errors

While working on the changes for 0.6, I started to get these errors. They went away after some time and I haven't seen them since (though I've used the Python client minimally since the 0.6 release). However, a user reported a similar experience on the forums today. I don't have steps to recreate, but wanted to make note of this as it's no longer isolated to my setup.

http://www.couchbase.com/forums/comment/reply/1001642#comment-form

Exception in thread dispatcher-thread (most likely raised during interpreter shutdown):
Traceback (most recent call last):
  File "/usr/lib64/python2.6/threading.py", line 532, in __bootstrap_inner
  File "/usr/lib64/python2.6/threading.py", line 484, in run
  File "/usr/lib/python2.6/site-packages/couchbase/couchbaseclient.py", line 661, in _start_dispatcher
  File "/usr/lib/python2.6/site-packages/couchbase/couchbaseclient.py", line 968, in dispatch
  File "/usr/lib64/python2.6/Queue.py", line 174, in get
<type 'exceptions.TypeError'>: 'NoneType' object is not callable