Version: 0.5 (using 4.4.3 (KDE 4.4.3), Kubuntu packages) Compiler: cc OS: Linux (x86_64) release 2.6.32-22-generic Sometimes when I start KSudoku and set difficulity level to hard, it in fact gives you an easy board to solve. Quitting the KSudoku application and starting it again doing the same and it may be that you get a board at hard level.
*** This bug has been marked as a duplicate of bug 217925 ***
I have replaced the puzzle generator and solver in KSudoku with a completely new generator and solver based on published algorithms. It will be released in KDE SC 4.8, due out in late January 2012. The new algorithms provide a full range of difficulties, from Very Easy to Diabolical and beyond, which have been tested against ratings of puzzles published in newspapers and on the Internet. Enjoy! See http://techbase.kde.org/Schedules/KDE4/4.8_Feature_Plan#kdegames for further details of changes to KSudoku in KDE SC 4.8.