I\'m making some program with python3 and XLib.
On my PC with Ubuntu 14.04 everything works fine but when I try to run my app in my notebook with manualy installed Xorg
Ok, It was bug in python3-xlib. See https://github.com/LiuLang/python3-xlib/issues/6 for details.
Temporary workaround is
$ xhost +
http://ubuntuforums.org/showthread.php?t=2290602