I was talking with the Principal Flutist of the Florida West Coast Symphony once. I asked her the same question when I asked her about my tone in the third octave. She told me to NEVER use the D# key when playing High B...especially if you are going to a C after it. Keep the pinky away from it so that you can use it on the High C. I have practiced my chromatic scale over and over to get that down...and the High C comes out clear as a bell right after the High B without the D# key. Of Course, that`s our $.04 ($.02 from each of us)

-Dennis