Ctypes debug of dll function

[Massi]

Hi everyone, I'm pretty new to the ctypes module and I'm encountering
a problem. I'm working under windows xp with python 2.5 and in my
script I use ctypes to call from a dll some functions I wrote in C.
When I call one of these functions it happens that my script crashes
raising the following error:
WindowsError: exception: access violation writing 0x00000000
My question is...is there a way to debug my C function from the dll
while it is run from the python script?
Thanks in advance for the help.