Been trying to prolong my battery life by changing syncing etc and have come across a prob with my calendar. I originally signed in to sync the calendar with my gmail one, but now i want to change that so it doesn't. everytime i go onto the calendar app it states not responding and have to force close, then i went on the battery thingy me bob and it says calendar is 49% and when i click 'force stop' it doesn't do anything. help 