I don't know how it happened, but now I have a track labeled as "Master" on my timeline and I can't seem to get rid of it. It's eating up part of the viewable area of my timeline and is pretty distracting.
That happened to be a while back and man was that irritating.
Finally I just opened a blank project and started pushing every key on the keyboard until I hit the "B" key (as it was the audio bus that was showing - not that I knew what that was, persay)