Installing Kali 2.0 and boot loader to external USB harddrive

I also posted this in the install thread but I think it might get more support here instead of buried in a very long thread with lots of other issues.
I am trying to install Kali using the install routine when booting from CD (tried both x32 and x64) to an external usb hard drive so I can take it with me to isolated networks, boot off of it from a laptop or whatever is available, reconfigure the ip address, and start testing. This has worked great with v1.x but when I go through the install routine and chose the external usb hard drive as the target and then chose to install the boot loader on the usb drive, instead of local, it never boots to the USB when chosen in the bios. I have tried this with two different usb enclosures,each with different hard drives, on two different workstations. The boot completely hangs and never loads GRUB. Anyone else had success doing this?