Reloading modules

[Duncan Smith]

>>> from Graph import *
.
.
.
>>> reload(Graph)
Traceback (innermost last):
  File "<interactive input>", line 1, in ?
TypeError: reload() argument must be module

What do I need to do to successfully reload a module?  I'm currently wasting
a lot of time re-starting PythonWin each time I want to test a changed
module and I can't find the answer.  Thanks

Duncan