If you are using Internet Explorer, double click this icon in the bottom-left of your window when the problem occurs:
You will get a description of the JavaScript error... please copy it here and then I can probably fix this!
If you are using FireFox click on Tools -> Error Console. Then click the Errors button to filter out warnings, and scroll down to the bottom to get the most recent errors. Copy and paste the Speed Sudoku error here.
Thanks
