I have the same problem but with a different source. I keep having invites reappear after the meeting has occurred. So now I have an invite where the only responses are maybe/decline/accept ... all of which send an email to the client AFTER the meeting has already taken place.
Why can't I just delete an invite without iCal FORCING the email acknowledge of some kind. Why do other people have so much control over my calendar app?
Hmm- yeah- it sounds like a different problem that could use the same solution I'm looking for.
In MobileMe it was easy enough as you could backup your calendar to a file, edit the file, hack out the offending entries, and then wipe out your MobileMe calendar and sync from the saved version (by telling it to use the version on your Mac as the canonical version).
You can't do that in iCloud.
I've got a call open with Apple on this issue right now and they are saying that there's no real way for them to remove the errant meeting and I'll probably have to wait until it expires in December (and just be very careful not to accidentally alter the meeting causing lots of notifications to be sent out).
However they are still looking into it in the hope that they can find a solution. Watch this space.