Hi Both, I have been having this issue too. Sometimes it hangs when restarting system after imaging. I seem to have a solution/work around. The first thing to look at is the SATA operation in the BIOS, my system only boots successfully when ATA is selected. The second is to look at the boot order, for some reason I have to have the HDD listed first. (This means yourll need to hit F12 to select network interface everytime you want to setup a new pc. Not ideal, but works) Lastly, try updating the kernel. This can be done through the fog interface normally, but the latest version doesnt seem to install correctly. You can download this from the sourceforge website.
I Hope this helps!