This annoying behavior is that from time to time the additional calendars on my google account get repeated in the gmail account section and then in the Delegates section. I don't mind where they appear, at my account section or the Delegates, but the problem is that they appear on both sections and the events get duplicated.
I uncheck the ones on the account section and check the ones on the Delegates and all look all right but then the calendars on the account section disappear and after a while they reappear and duplicate the events again. It's getting very annoying.
Best Answer
After extensive research, it seems google knows about this, and apologizes and is working to fix it.
http://productforums.google.com/forum/#!topic/calendar/AWJSWllOt9Y/discussion