» Sat Aug 28, 2010 5:41 pm
I constantly ran into problems with Jack and Loyal after doing the missions in Nellis. Theres a few known glitches surrounding Loyal. Luckily if you're on a PC some of them may have work arounds.
http://fallout.wikia.com/wiki/Loyal for more information (scroll to the bugs section). Perhaps it can help you isolate the problem and figure out why Loyal disappeared when he did.