Ok, so I heard that people tend to lose there companions but didn't know how, now I do. I told my companion (Cass) to go to the lucky 38 while I did a quest, I went back to the lucky 38 and she was nowhere in sight, so I waited for about a week and nothing! anyone know where she could of gone to or how to get around thish bug once it is in place, by the way i have gone back to the outpost and we parted ways at camp searchlight. (I think its called)

This thread has a few things you may try:

http://www.gamesas.com/index.php?/topic/1131451-for-missing-companions-message-to-devs/