/usr/lib/pyshared/python2.6/gtk-2.0/atk.so is in python-gtk2 2.24.0-3+b1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/pyshared/python2.6/gtk-2.0/../../../python2.6/dist-packages/gtk-2.0/atk.so