Have you done the most recent updates from the weekly builds?
In the last couple of builds (last couple of weeks) - launch_manager is now running which should start your exec if it is specifically named in the database (otherwise it looks for a binary of device_name with spaces replaced with underscores) - though to be honest I haven't thoroughly tested the custom binary name execution part just yet (though I fully expect it to work)
First lets make sure you have the latest weekly build updates by running
sudo apt-get update
sudo apt-get dist-upgrade
If it still fails to launch after you are sure you are at the latest build, please post back here as I have interest in making sure it works correctly.