Default [Q] how to remove root files after nb1 update

I was rooted on 4.3 and then I unrooted abd did it a update to nb1. Now when I try to use ISIS it says phone has been rooted. I know there is a work around but you have to be rooted for it. Is there a way I can remove whatever file ISIS is seeing that is making it think three phone is rooted when it's not.