Debian :: Make A Script Run When X Is Started To Set The Desktop Background Using Xloadimage

I'm trying to make a script run when x is started (to set the desktop background using xloadimage, run xcompmgr, and make one change with xmodmap [I suspect there is a better way to change this]). The wiki says (on the subject of .xinitrc) "If you want the script to be called when ever an X Session is started, then you should instead use ~/.xsession" I had no default ~/.xsession file. I believed that it would be checked for, so created a minimal file

#!/bin/sh
touch /home/user/this-script-ran
exec /usr/bin/xmonad
and gave it executable permissions (744).
"allow-user-xsession" is present in /etc/X11/Xsession.options.
However, ~/.xsession does not run when x starts.

1) Should I be using something other than .xsession for this?

2) If not, how do I enable it? Or am I making some error that prevents it from running?