Great game but some bugs

Its a great game - easy to use, and the tutorials are helpful. Unfortunately, it randomly switches from pencil to permanent and if you arent paying attention it messes up your whole game. Not sure why it does it, and only happens occasionally in some squares. In one square it will put the "pencil marks" and in the next a permanent, and then move back to pencil. VERY frustrating!

LMLsoccer about (heart) Sudoku, v1.1