Sometimes your body will only respond to certain low amounts of carbs, almost like it rejects having too little, and too many make you gain weight. Having a naturally meso-endomorphic body type I also am very sensitive to carbs and have to find the right amount. What I have found with me is I get down to a certain low point in carbs, usually around 60-100g a day and I plateau in weight loss. How I have found to beat it is adding more types of cardio and bumping up cardio in general.
My suggestion is to hit different types of cardio, Lot-int Incline, Eliptical, Bike, HIIT and also try bumping it up 5 minutes or so each week and keep carbs moderate. See if the cardio will help with weight loss.