AttributeError when freezing library with multiprocessing

Question

I want to freeze my program, which includes a library that uses multiprocessing (http://pyevolve.sourceforge.net/), with py2exe. This works just fine; I can run the generated .exe and (with multiprocessing disabled) my program does what I expect it to do.

My problem occurs when the multiprocessing is enabled. At first my program was completely started again for every CPU core. I fixed this by adding freeze_support() to the library where the process pool is created. This fixed one issue but created another: Now every worker in the pool creates the following AttributeError:

Process PoolWorker-XY:
Traceback (most recent call last):
  File "multiprocessing\process.pyc", line 258, in _bootstrap
  File "multiprocessing\process.pyc", line 114, in run
  File "multiprocessing\pool.pyc", line 102, in worker
  File "multiprocessing\queues.pyc", line 378, in get
AttributeError: 'module' object has no attribute 'my_multiprocessing_fct'

This is the part of the library where the multiprocessing is started:

 ...
 if self.multiProcessing[0] and MULTI_PROCESSING:
     proc_pool = Pool(processes=self.multiProcessing[2])

     if self.multiProcessing[1]:
        results = proc_pool.map(multiprocessing_eval_full, self.internalPop)
        proc_pool.close()
        proc_pool.join()
        ...
     else:
        results = proc_pool.map(multiprocessing_eval, self.internalPop)
        proc_pool.close()
        proc_pool.join()
        ...
...

And the freeze_support() I added on top of the code:

try:
   from multiprocessing import cpu_count, Pool, freeze_support
   freeze_support()
   CPU_COUNT = cpu_count()
   MULTI_PROCESSING = True if CPU_COUNT > 1 else False
except ImportError:
    MULTI_PROCESSING = False

The code works perfectly fine when started from my IDE but not via the generated .exe.