Sounds like you're not doing anything wrong. I've been in your same situation in the past. At one point, I think I might have even gained a pound or 2. Then, I broke through the wall and dropped the weight.
Have you considered weightlifting? This helped me. The more muscle mass, the more your body has to maintain so the more energy it has to burn to do so. Hence, you'll need to burn more calories. If I know I'm eating healthy (no simple carbs/sugars, lots of fiber, fruits&veggies with a GI of 60 or lower), and exercising, I don't count my calories. What I do do is exercise a little longer & focus a bit more on the weights.
Also, I switched to working out in the a.m. I knew I lost weight better but didn't know why. I now know that the body has to use reserves (stored body fat) for energy. You can burn up to 300% more by working out in the a.m. before eating.
Your biggest muscles are your thighs/butt, chest, & lats (back) so work on bulking those to get the most bang for your buck. I think that should do the trick. It did the trick for me.