Hello,
I am sorry I should have included more information.
I have FOG v 1.2.0 running on Ubuntu 14.04. The laptops are PXE booting into FOG and I am ale to answer the questions. When I reboot the devices will connect to FOG and it appears that they are going to image; however, when the imaging process is complete the devices are not imaged and the screen is like the one in the picture below. Like I said earlier, I have successfully imaged this same model on about 30 devices and I have about 20 that will not image.
Any help you can offer would be appreciated.