When engaging Driver Nephi and other fiends the game gets choppy and certain sounds can't be heard (guns, pip-boy, etc). After about a minute or two the game freezes (regardless of the outcome of the battle).

I've tried quickly killing Nephi and grabbing his head then running straight to Camp McC, but I still experience freezing. In addition, I have Boone as a companion.

Freezing occurs consistently and prevents me from continuing the game.