I am trying to get rid of so many calendars that the "system" keeps creating. It seems to me that this and the fact that duplicate contacts keep getting created. I thought all this stuff works together, iMac, Windows PC, iPhone, iPad(s)........ But nobody wants a new duplicate calendar and new duplicate contacts, why doesn't "it" ask before it does this automatically and drive us crazy? How do I get rid of them? I gave my iPad 1 to my wife and turned off all syncing everywhere I can find it and the calendar seems to still sync to my calendar.
Do you have MobileMe? Are you syncing your calendar using that? If so, are you also syncing your devices using iTunes? - that is likely to produce duplicates, indeed multiple duplicates. If this is the case you should stop syncing with iTunes and stick to MobileMe. Turning off calendar syncing in System Preferences>MobileMe>Sync has no effect since iCal no longer syncs using that method.