What confounds me is the fat around my stomach/tummy refuses to budge!!!

My workout schedule: 3 times cross trainer, 2 times bicycle, all for 45 mins. Oh don't get started on situps because they only tone the inner muscles, but the outer layer of fat must be burnt off. But anyway I've been doing my situps too, so religiously that my muscles are a firm wall of toned cells. Just that miserable glob of fat above the muscles that are oh-so-stubborn to move.
Well definitely if I have a personal trainer I can see better results but the fact is I don't, and currently relying on myself.
Diet-wise, a cereal drink for breakfast, a big tuna sandwich for lunch, and a wholesome salad for dinner.
So you see, i'm cutting back on calories, and yes i'm seeing results but I don't understand why I'im still having a clump of fats at my tummy.
Oh by the way my stomach got this way when I went overseas for a short stinct and had very oily and salty meals.
How?? Help!