Rocky:
is the problem that you build muscle very quickly in the glutes (in which case maybe cut down on the lunges and squats) or that you can't lose body fat from this area?
If it is the latter, perhaps try to vary the cardio workouts that you do (especially if you feel you are in a rut): kick boxing will target this area beautifully, power walking or running can also help. Basically, if you perform the same cardio workout all the time, your body will have gotten used to the exercises you perform and you may have plateaued out here. Jolt your system with different kinds of cardio.
They do say that it is hard or impossible to target fat loss from particular areas of the body, that weight loss will come from all over. There is an article in the March 2002 edition of Fitness magazine --although some Cathe fans dislike the mag-- targetting this exact issue and also Shape mag of December 1999 has a special on cardio workouts of benefit for the glutes area. This is an old issue I picked up from a library clear out, perhaps your local library stocks back issues? If not, I could send you a copy...
Experts also talk about creating the illusion of smaller lower body by balancing out the top half to the lower half. Do you feel you need to up the ante on the upper body weight training?
My last piece of wisdom: my legs and butt are never in better shape than when my partner and I head to the hills/mountains and spend our vacation back packing. With either a 40 pound pack on your back --like Cathe's barbell weight for squats-- or a child in a kidcarrier on your back going uphill, it is the best...so if you live near some hilly terrain, you know what to do!
Hope any of this helps
Clare