Linux game in Xubuntu 12.10 no longer prints
 

I use the Sudoku app in Xubuntu to generate puzzles and print them. Suddenly the program refuses to print (have tried two combinations of computer and printer). The print command gets to thee final stage, but does not show paper size (greyed out) and does not print. Downloaded Sudoku puzzles can still be printed, but something seems to be bloaking the Sudoku generator in xubunbu. Mystery!