Event handling for COM object with win32com (pywin32)

Sun Jun 22 05:15:12 EDT 2014

Dears,
I have a problem with firing Events and event handling on COM object.
This code works on python console but there is no event fired.
>>> class fmstrEvents(object):
 ... def OnRecroderDone(self):
 ... print "Hello OnRecroderDone"
>>> import win32com.client
>>> fm = win32com.client.Dispatch("MCB.PCM")
>>> fm_events = win32com.client.WithEvents(fm,fmstrEvents)

The application fmstr with COM Object "MCB.PCM" is freezing by events handling within python by pywin32.
Do I miss something in code or incorrectly handling the events or COM Object?
Thank you very much.
Peter