Change clef, start note entry, crash

1. Create new score (such as violin)
2. Drag a new clef to the start of the the score (such as bass clef)
3. Press N to begin note entry
4. Click on staff to add note

MuseScore crashes

Tested using r.1938, self-built, Windows XP

First reported by fsx: http://musescore.org/en/node/2058