Perhaps your calories have creeped up on you. I know it happens to me if I am not careful. Paleobird has a long thread somewhere about calorie counting revisited and some suggest that for some, especially women, counting calories even while primal is important. Nuts, nut butters etc are easy to overeat for many.
Also, and this is a small thing, you refer to this as the 'caveman diet' which it is not. Have you read the Primal Blueprint? If so great, if not please read it as often going by what friends say is not the same as doing it correctly. I know this from experience as the friend who turned me onto Primal told me what the way of eating consisted of and then I read the book and they were not the same.