Comment 5 for bug 338978

Thanks, that narrows the problem to the python xrandr bindings and/or ctypes. There may be a problem with your python ctypes installation. It looks like a bug #285411; could you please verify that it is the case by running the following:
   grep ^__version__ /usr/share/pyshared/ctypes/__init__.py
   strings /usr/lib/python*/lib-dynload/_ctypes.so | grep 1\.\0\.
if these numbers are different it is the culprit.