Do you honestly track every single thing you eat and drink, including the "occasional" day off? Do you weigh and measure portions, or "eye ball" them? Are you sure the calorie burn shown on the machines are accurate? Do you add sleep to your "lifestyle" in the calorie burn calculator?
At 260 pounds, with daily exercise and being male, my daily burn comes out to around 2800 cals. I run around a 1200 cal per day deficit, monthly "day off" included and average from 2.5 to 3lbs per week loss (which is right in line with what the "math" predicts).
I just have to think that you may be overestimating your burn, underestimating your calorie intake, or both.
PS How is your water intake and your calorie mix?
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.