When I Alt+Doubleclick on an event, the focus changes to the key editor and shows the notes of the event inside. In earlier versions of Studio 1 only the horizontal zoom was adjusted. Since (I think) 4.6 also the vertical zoom was adjusted to show the highest note on the top and the lowest note on the bottom of the key editor. Because I often want to paint new notes (for example add an octave) this is very annoying, because i always have to readjust the vertical zoom with my mousewheel.