I have the same problem.. dam hot cheetos. Lately I've been bring fiber one cereal in a bag to work. That's been satisfying my urges for stuff like chips.
I would just stick with what your doing.. A small bag of chips isn't going to wreck anything. Overly strict diets often fail and I don't really believe in them. Consistency is more important in my opinion. Good luck!
Chex mix! :)