I have encountered a bug with the scenarion information panel not reflecting the difficulty level.

• I started Djedu on normal and placed a few buildings. I saved the game.
  
• I restarted the mission and selected hard difficulty. Everything OK.
  
• I reloaded my saved game. The costs indicate that I am playing on normal, but the scenario information says I am playing on hard.
  
• I loaded my saved version of the first tutorial (played at normal) and the scenario information shows 'hard'. The costs indicate 'normal'. I let the tutorial complete and selected 'play next mission'. The next mission starts and the default difficulty is now hard.