Hi Pappocom,
I have some suggestions for making the program even better.
1. When dubbing have the current number either as the cursor or attached to the cursor. This would make using the mouse wheel a very attractive proposition. At the moment you have to either keep a mental note of which number you are on, or keep on looking up at it. Having the current number directly in your visual field would cut down dubbing time/effort dramatically.
2. Allow ascii import/export (i.e. cut & paste) of puzzles.
Here is a sudoku program which allows ascii import/export:
http://www.sudoku-solver.com/
3. When dubbing have the right mouse button as erase
Do any/all of those sound easy/desirable enough to implement??
Vin.