Was there a factory recall for wiring harness rub-throughs on that 2009 as there was for the 2008?
If there is a rub-through in the area of the tank, it can fire the plug with the tank off, but short out while ridding with the tank on.
Yup, I believe that the recall also covered some of the 2009 models as well. Easy to check as well, just have a dealership run the VIN to see if the work has been done yet. If not they will repair it for free. Same with the signal lights and muffler recalls.