WaitCommEvent problem on windows XP

[jim]

Hi, All
I am using python (activestate 2.2.2-224) on XP home and have suddenly got
the following error from a file which works fine under millenium.

File "E:\code\Python\PyModbus\FEModbusV101.py", line 162, in ComPortWrite
rc,mask =win32file.WaitCommEvent(self.hComm,self.Overlappe d)
api_error: (87, 'WaitCommError', 'The parameter is incorrect.')

self..hComm is a proper handle to the comm port
self.Overlapped is a proper overlapped object

I think the api call requires 3 parameters but only 2 are used in python
I have checked through old messages and found quite a few about this but saw
no solution ?

is it me ?

any help gratefully received.
regards
Jim