What do you do when what always worked, doesn't work?

I am experiencing this in my classroom now. It is a confusing feeling. Naturally, we teach procedures and routines at the beginning of the year. Usually after 10 days of said instruction, the children are well versed on the ways of the classroom. But what do you do when they're not? Of course, you reteach! What happens after you have retaught and things are still the same. Using an idea of Dr. Long's, it's like losing your identity. You follow Harry Wong and Beginning Teacher Survival Guides all those years and it works like a charm. Now six years in, you are doing the same and nothing... We all know not much instruction can occur when a classroom is not well managed. I feel so defeated! Can someone please give me some suggestions?!