Nikon D90 Autofocus to Manual Switch?

Hi

I bought my Nikon D90 just a few weeks ago and I noticed that the switch on the left side from A to M doesn't flip back and forth like it used to. I don't know if it's just my imagination, but doesn't it cleanly switch and click from A to M and not stop in between? It does go to autofocus on A, but I don't feel comfortable keeping it if it is stopping in between the two options if it's not supposed to. Does anyone know if theirs stops in the middle?

I love my D90, but mine does stop in the middle very often. Try to use a air brush or compressed air to blow out smaller particles, but it happens to me too.