I am using a Motorola Droid 2 with Verizon, and in my Calendar, i recently had a coworker share their calendar with my gmail. Since that time, rather than default to show my personal calendar, the phone's calendar instead defaults to NO calendar, and every screen change reminds me with the message "There are no calendars selected!" How do i force my phone to recognize my own calendar as a default so that it no longer selects no calendars?