slim but fat belly

hi,
i used to be a slim person, then i developed a bad habit- i used to eat a lot and then go to sleep, then i started developing belly......
i hav tried everything ...a lot of aerobic exercises(basketball, swimming, crunces)

asa result of crunches i can feel the solid muscles but the belly still persists.....

i dont hav any gastric problem......

another thing is that when i holds my belly not much fats come in hand as compared to other pot bellied people....i can touch the solid bladder just under my skin,,,,,but the belly still perstists...

plz guide me what 2 du about it.....