After the IOS5 update my calendar started acting erratically. I would tap on an event and the calendar would close. Now when I open the calendar it opens for a second or two and then closes. I live by my calendar and have not seen anything posted on this issue. I have tried various methods to fix this (cold boot with it plugged into iTunes, reset, etc.) but nothing seems to work. Worse yet, because the calendar is a resident app you can't delete it and re-import it. Does anyone know of a fix for this issue?