I just bought a Keurig 2.0 brewer. Everything I'm reading says it will work only with K-cups that have the Keurig Brewed logo, the little black circle with lettering inside. I have such K-cups, and they don't work. Now I'm hearing that the outer ring on the K-cups is what determines whether or not a K-cup will work in the 2.0 machine. Is all this true? The Keurig Brewed black circle logo is meaningless?