CherryPy not playing nicely with win32com?

[infidel]

I've been trying to get my CherryPy server to authenticate users
against our network.  I've managed to cobble together a simple function
that uses our LDAP server to validate the username and password entered
by the user:

# ldap.py
from win32com.client import GetObject

ADS_SECURE_AUTHENTICATION = 1

def login_valid(username, password):
    ldap = GetObject("LDAP:")
    try:
        ldap.OpenDSObject(
            'LDAP://XXXXXXXX.US',
            'XXXXXXXX\\' + username,
            password,
            ADS_SECURE_AUTHENTICATION
        )
        return True
    except:
        return False

This function works great if I call it from the interactive prompt:

>>> import ldap
>>> ldap.login_valid('mylogin', 'XXXXXXXX') # pass incorrect network password
False
>>> ldap.login_valid('mylogin', 'XXXXXXXX') # pass correct network password
True

But as soon as I have my CherryPy filter call this exact same function,
I get an "invalid syntax" COM error:

Traceback (most recent call last):
  File "C:\Python24\Lib\site-packages\cherrypy\_cphttptools.py", line
77, in _run
    applyFilters('beforeMain')
  File "C:\Python24\Lib\site-packages\cherrypy\_cphttptools.py", line
461, in applyFilters
    method()
  File "filters\authenticate.py", line 29, in beforeMain
    if ldap.login_valid(username, password):
  File "K:\src\py\XXXXXXXX\filters\ldap.py", line 6, in login_valid
    ldap = GetObject("LDAP:")
  File "C:\Python24\Lib\site-packages\win32com\client\__init__.py",
line 73, in GetObject
    return Moniker(Pathname, clsctx)
  File "C:\Python24\Lib\site-packages\win32com\client\__init__.py",
line 88, in Moniker
    moniker, i, bindCtx = pythoncom.MkParseDisplayName(Pathname)
com_error: (-2147221020, 'Invalid syntax', None, None)

I don't get it.  How can it be ok at the >>> prompt but invalid under
CherryPy?