It could be as simple as overtraining them.
The Abs are muscles just like any other part of the body and need time to recuperate from a heavy-intense training session. Training them every day doing numerous sets and reps, plus the workout they get when you do all of the other power excercises in your routine is overkill.
If you keep pounding them day after day with any considerable rest you wont see much if any improvements as the muscles don't have time adapt and grow. If you following an intense training program you should be training your abs anymore than 1-2 a week tops. In this case less is more.