General Unable to modify calendar in S Planner

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http://androidforums.com – when i select an event from S Planner, i see it belongs to calendar, saying lunch. but when i edit the event, the calendar section is all grey out, thus i am unable to change the change from lunch to another calendar. is this a bug with S Planner?? however, when i open the same event with another calendar app (calengoo), when i edit the same event, i can change the lunch calendar to something else. (General)