I would recommend mixing up your workout. Not sure what is at your gym but at mine there are 3 types of ellipticals. All focus on a different muscles and I can burn more calories on one of them more than I can on the other two.
As far as mixing up the workout maybe try a brisk walk on the treadmill for 45 minutes at an incline and then hop on the elliptical for 45 minutes. In between cardio maybe add in some weights for conditioning and toning. Also if you are a member of a gym consider taking the classes.