I found a bug in the campaign mode!
When you finish a mission, you can view all of the scores.
Now hit "Done" to start the next mission.
Now hit "Back" to go back to the campaign screen.
Now tell the campaign to continue.
Whoops! Since there's no savegame corresponding to the current mission, things act weird and can crash!
You can fix this by reloading the last savegame and winning the mission again.