Sync'ing iCal and Calendars
I have an iMac running under OSX.6.8 with iCal v4.0.4 (1395.7) and an iPad  running under iOS 5.1.1 (9B206) and I want both calendar applications to stay in sync.
I sync via iTunes and not iCloud.
If I make an appointment in iCal, it appears on the iPad - fine. If I then amend that appointment, either in timing or even moving to to another day, on the iMac the amended appointment appears and yet the old appointment stays there, it is not "deleted".
Equally, when I make an appointment on the iPad, it does not get transferred across to the imac when the two devices are sync'd.
I am, no doubt, being myopically stupid here, but why do the two not stay in sync, presenting me with the "latest version" of my "combined" calendars?
Unless and until I can do that, the ipad version seems pretty well pointless!
Thanks in advance.