Using Python 2.5.4 and Python 2.6.1 on 32-bit python, when passing a
regular string to a function expecting pointer to a wide string
(wintypes.LPCWSTR), the function executes without problems.

When calling the same using Python 2.6.1 on 64-bit windows, the called
function appears not to recognize the parameter unless it is first
converted to unicode.

I discovered this when calling the WNetAddConnection2 function.

Assuming a properly-initialized NETRESOURCE, resource.

password = None
username = 'username@domain.com'
flags = 0

val = ctypes.windll.mpr.WNetAddConnection2W(
  ctypes.byref(resource),
  password,
  username,
  flags)

This method works fine on 32-bit python but fails on 64-bit python
unless username=unicode(username).  The error returned is "The specified
password is incorrect", indicating that the username is in fact
incorrect because the correct username does not require a password.

I wish I had a better test case; I'll try to track down one that doesn't
require such a complex underlying API.

I'm not sure what the correct fix is for this, but regardless, I would
expect the behavior to be consistent for the same Python version
independent of word size.