Can't enter notes using keyboard

Just installed 1.0 and found my old scores mostly coming out pretty nicely.

However, when I tried to create a new score, I found that I can't enter notes using abcd keys. I can enter notes using the mouse, but that obviously is impractical. Further, the program does not repond to N, 1,2, 3, 4, etc. keys either. I realize that I must not be doing something right or there would have been a howl from other users already. I am using Windows 7 ultimate. Please show me the way. Thank you.

Ying-Da