My computer reverted the desktop image back to the default image upon booting. In system preferences it showed that my preferred background was still the one selected. I clicked on the default image and then on the one I wanted and it returned to the way I wanted. Does anyone know why this may have happened? I'm running 10.8.2 so it could be an error Apple still has to work through with the OS. I'm not very familiar with programming of computers so I don't really want to make too many guesses on what it could be.