Recurring events in Leopard iCal that refuse to be deleted

The futility of deleting recurring events in iCal
I’ve charted my contempt and loathing for Mac OS X 10.5 Loathsome Leopard elsewhere, so won’t go into that again in too much detail, other than to note that I could probably double my original list of gripes. One of the problems it has caused me is that I’ve been unable to permanently delete recurring events in iCal. Sure, I’ve been able to delete them while iCal is open — but when I relaunched iCal again, those damned recurring events had … recurred.
One fix I saw on the Apple forums was to right-click the event in question, select ’stop recurrence’ and then delete the event. This didn’t work for me, though.
I even tried exporting the relevant calendar to Mozilla Sunbird, deleting the recurring events there, and reimporting into iCal — but amazingly, yet again, the recurring events pop up on relaunching iCal.
Have you had features that worked perfectly in Tiger break in Leopard? Has the ‘world’s most advanced operating system’ got you feeling you’re encountering that ol’ Windows blue screen of death, in spirit if not in actual form? My brother, a reasonably contented Leopard user, suspects my problems relate to running it on an iBook, and not on an Intel machine: thoughts? I have seen a number of hits land on my blog from search queries like “Leopard downgrade” and “restore Tiger” — so clearly I’m not alone in this experience — and only the hassle of reverting to Tiger has stopped me doing so. I might yet.