There have been major improvements made in the area of your problem on FOG Trunk. Also, 1.2.0 has known instabilities on Ubuntu 14.04 and newer. These instabilities are also fixed in FOG Trunk.
Here is how you would upgrade to trunk: https://wiki.fogproject.org/wiki/index.php/Upgrade_to_trunk
If you don’t wish to use FOG Trunk, you’ll have to wait for help from someone more experienced than myself.