I think this bug still exists in Python 2.6.4, and I haven't tested 2.6.5, but since 2.6.4 was released 6 months after this bug was closed I assume it's still an issue. Running ndbecker's test program as is produces the following output on Solaris 10:

Process PoolWorker-1:
Process PoolWorker-2:
Traceback (most recent call last):
Traceback (most recent call last):
  File "/opt/app/g++lib6/python-2.6/lib/python2.6/multiprocessing/process.py", line 232, in _bootstrap
  File "/opt/app/g++lib6/python-2.6/lib/python2.6/multiprocessing/process.py", line 232, in _bootstrap
Process PoolWorker-3:
Traceback (most recent call last):
  File "/opt/app/g++lib6/python-2.6/lib/python2.6/multiprocessing/process.py", line 232, in _bootstrap
    self.run()
    self.run()
  File "/opt/app/g++lib6/python-2.6/lib/python2.6/multiprocessing/process.py", line 88, in run
  File "/opt/app/g++lib6/python-2.6/lib/python2.6/multiprocessing/process.py", line 88, in run
    self._target(*self._args, **self._kwargs)
    self._target(*self._args, **self._kwargs)
  File "/opt/app/g++lib6/python-2.6/lib/python2.6/multiprocessing/pool.py", line 57, in worker
  File "/opt/app/g++lib6/python-2.6/lib/python2.6/multiprocessing/pool.py", line 57, in worker
    self.run()
    task = get()
    task = get()
  File "/opt/app/g++lib6/python-2.6/lib/python2.6/multiprocessing/queues.py", line 352, in get
  File "/opt/app/g++lib6/python-2.6/lib/python2.6/multiprocessing/process.py", line 88, in run
  File "/opt/app/g++lib6/python-2.6/lib/python2.6/multiprocessing/queues.py", line 352, in get
    self._target(*self._args, **self._kwargs)
  File "/opt/app/g++lib6/python-2.6/lib/python2.6/multiprocessing/pool.py", line 57, in worker
    return recv()
    return recv()
TypeError: type 'partial' takes at least one argument
TypeError: type 'partial' takes at least one argument
    task = get()
  File "/opt/app/g++lib6/python-2.6/lib/python2.6/multiprocessing/queues.py", line 352, in get
    return recv()
TypeError: type 'partial' takes at least one argument