Well, that's the rub in this game--everybody and every body is different. I feel pretty good at 1500-1600 cals but then, I don't exercise to the extent you do.
Of course you want to feel good, and you want to have enough fuel for your muscle building efforts and (most importantly?) you don't want to be overly hungry on a regular basis.
Many people have found better success being a little more protein heavy, even temporarily. I try to keep my pie chart, on average (I don't do The Zone thing where every single meal is supposed to be 40/30/30) around 40/30/30 but if I err, I try to make it on the protein and/or fat side rather than the carb side.
Really, if you are keeping a decent calorie deficit, you WILL lose. Perhaps you are just on a little plateau--they do happen to all of use along this journey.
Just some thoughts to mull over. Generally, if what you're doing isn't working, it's time to try something else--often only a small change can have a big effect.
PS Thanks for the nice comments--I've sort of taken the weight loss fairly slow this time around as I intend for it to be my last time. Of course, that remains to be seen but I am optimistic!
47 M 5'8"
May 4, 2010...... 440? lbs. (Start FitDay Size 60 Jeans)
June 19, 2010.... 393 lbs. (First Weigh-in)
June 19, 2011.... 229 lbs. (164 lbs. gone in one year :-)
Current Weight... 185 lbs. (Size 36 Jeans)
Next Goal 169 lbs. (07/04/12)
Ultimate Goal 165 lbs. (12/31/12)
The best exercises for weight loss are Fork Putdowns and Table Pushaways.