See bold. To the OP - are you using Optimum Nutrition Casein? It's the greatest! I've had the chocolate and vanilla; if that is the brand you're using, just wait until you try the vanilla!
I've had both those flavors, my favorite is the cookies n cream by far.
OP, you mixing it with water or milk? I'm going to start throwing in some natty pb, i've been drinking 2 scoops with 2 cups milk.