This is a re-write of my badly composed post from earlier today....
My desktop iCal app is exhibiting very odd behavior lately. Newly scheduled (future) events disappear when I quit/open the app. Alarms are late by random amounts of time 1.3 hours, 2.4 hours and not because of time zone settings - I don't use the snooze option. Also, certain events won't delete - I highlight the event, press the delete key and respond to the dialogue box but the event remains on the calendar.
I'm losing appointments and spending excess time managing my schedule - it's obviously pretty frustrating.
FYI - I do not Sync to iCloud nor do I Sync to Mobile Me. I do, however, sync with my iPhone 5.