Well, being a bit short of time (and an alleged alpha type male who always rushes ahead of common sense!) I followed your instructions and added a few thoughts of my own along the way - specifically that iTunes might somehow be implicated in this curious affair as that was being used for the syncing. process.
The result is, I hope you'll be delighted to know, success - syncing is now back to what I would have expected and what nature intended.
For now that is, because there have been false dawns before and I expect the problem to return and haunt me again at some stage.
But next time I'll be ready and will know how to confound and defeat the Apple Agents of Confusion!.
What I did was ...
backed up iCal to the Desktop in case it all went horribly wrong;
sync'd without iCal/Calendars being checked in iTunes and thus all iPad calendars were initialised;
powered off the iPad to remove any "RAM" type data being maintained;
as earlier, deleted the iCal plist and all iCal/Calendar cache files but this time not only from the main user but from my DropBox and MacMate on-line back-ups (but not from Time Capsule as I wanted to have a fall-back position if it all went pear-shaped) by using Spotlight to look for all Calendar cache files wherever they might be. I found a number of "document" files called Calendar Cache 17-22-4n n, one per day, stretching back to 23 03 2013 and these were located in my Dropbox folder. Maybe that's the date when the current errors started to arise? I really can't remember, but why would the iPad be looking for such files in my DropBox folder? Most odd.
reset the SyncServices folder;
deleted the iTunes plist in case the "memories" of earlier appointments were in there - a long shot and probably a useless step, but I couldn't see any harm in doing it;
logged out of my user and then back in again;
relaunched iTunes to recreate a clean plist and then reset my preferences. Quit iTunes;
relaunched iCal to recreat a clean plist and then reset my preferences;
turned on the iPad and connected it via USB lead;
opened iTunes and reset the syncing options which were erased by resetting the SyncServices folder ealrier;
sync'd the two devices. iTunes reported that the iPad was "sync'd with another user" and asked if I wanted to Merge the data or Replace the data on the iPad - I guess that meant all data and not just iCal data as the latter had been cleaned from the iPad in the second stepo above.
Selected Replace data and sync'd;
entered a new appointment on iCal, another new one on the iPad and edited the times of an existing appointment on each device and re-sync'd ...
... and Robert's your mother's sister's brother's other brother! Or Bob's your uncle, for short.
Oh, I missed the final and most important step ...
breathed a sigh of relief and hit the caffeine!
I have no idea of which step is the one which resolved the issue so when (note when, not if) it happens again I'll repeat the process one step at a time (re-syncing each step) to see just where in the process the incorrect data is held.
I'll report back on this thread if I do manage to narrow down the steps to the vital one(s) as I cannot imagine that I'm the only person in the world experiencing this bizarre behaviour.
As I mentioned in other posts, this has happened more than once before but on those occasions it resolved itself without my intervention - save for me uttering a fair number of good old-fashioned Anglo-Saxon Oaths and Curses all the while the syncing was incorrect - and it was only recently that I noticed it corrected itself after an "iCal upgrade". That may have been a coincidence, though, as forcing an upgrade deliberately did not cure it this time.
So I'm pretty confdent it will happen again, but just what triggers this untoward behaviour is beyond me - I can't think of anything that I might do which causes it, nor can I begin to imagine from where the iPad collects the "historical" deleted appointment data which it then displays in addition to the "current" data on appointments. Nor can I think why it suddenly takes it upon itself to sync (albeit incorrectly) from iCal to iPad but not the other way round.
I didn't mention this before, but at one point I discussed this with an AppleCare Level 2 Support dweeb in Cork - and he was totally unable to fix it no matter what he tried, nor could he explain what was happenig and why!
Many thanks for your advice and patience - you may consider yourself a Level 3 (or higher!) surrogate AppleCare Genius! 😁
Message was edited by: iBozz to correct a few minor typos.
