Comment 1 for bug 794666

The problem is just a missing symbolic link. I assume libX11-6 is installed on your system. This command will solve it (on Ubuntu 11.04):

sudo ln -s /usr/lib/i386-linux-gnu/libX11.so.6 /usr/lib/i386-linux-gnu/libX11.so

If it doesn't help, type

find /usr/lib -type f -name "libX11.so.6"

to obtain correct path to file libX11.so.6 and create the link with your path.
Any of files omplexshutdown.py and complexshutdown.ui doesn't need to be executable (and probably shouldn't be).