[Chicago] Windows API ctypes bug

[Aaron Brady]

Hi guys, Just thought I'd ask about a weird bug.

Calling the Windows API through "ctypes".  The bug doesn't happen if: comment out another line, print before the call, call the ANSI version (instead of Unicode), run on the 32-bit build, run in 3.3, or run on a home-compiled build.  3.4-x64 and 3.4.1-x64 only.  But it does happen consistently (not even threading).  Program:

http://home.comcast.net/~castironpi-misc/gui%2002c%20mdi%20-%20bug%20fork%20markup.html

Error:

Traceback (most recent call last):
  File "D:\working\gui 02c mdi - bug fork.py", line 41, in <module>
    mdi_child= user32.CreateWindowExW( wd.WS_EX_MDICHILD, mdichild_wnd_class_id, "child window", wd.WS_CHILD, 10, 50, 200, 200, mdi_client, 0, 0, 0 )
OSError: exception: access violation reading 0x000000150000C268

If you could help out I'd appreciate it, even brainstorming since I'm even running out of leads at this point, since it works fine in the source.  For one, can anyone else get a repro in 3.4, or could it be just my machine?