Completed Sudoku game, but application did not detect completion or report error.

[DAP]

Binary package hint: sudoku

I completed a sudoku game, with no detected errors, but the sudoku application did not detect that the game was completed.
I will attach a screen shot.

Puzzle Statistics

Calculated difficulty: Very Hard (0.79)
Number of moves instantly fillable by elimination: 3
Number of moves instantly fillable by filling: 3
Amount of trial-and-error required to solve: 2

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: sudoku (not installed)
ProcVersionSignature: Ubuntu 2.6.32-25.43-generic 2.6.32.21+drm33.7
Uname: Linux 2.6.32-25-generic x86_64
Architecture: amd64
CheckboxSubmission: 4f08ac62e89ad166a1e0b05f95495253
CheckboxSystem: fd6c484c0b5d20a2f1cd036ef0f63975
Date: Wed Sep 15 22:04:21 2010
ProcEnviron:
 LANG=en_US.utf8
 SHELL=/bin/bash
SourcePackage: sudoku

[DAP (akadap)]

After reporting this bug, I sequentially, from the top left, selected each square and clicked on the "Automatically fill in the current square if possible" button, and when I did this to the "2" in the lower left corner, Sudoku suddenly figured out that I had completed the puzzle, and went through its normal color cycling.