Why do my meat burritos not heat well?
I agree with Brendan's answer above. Having also made freezer burritos ahead of time, I find that it helps if I put some source of re-heatable 'liquid' in the wrap while preparing them (e.g. salsa, not sour cream, for example). It might have something to do with steaming the food instead of directly heating it, maybe? Let me know if that helps.