I HAD the exact same problem. About a year after the recurring event ended I got fed up and tried to google it. So, after I read this thread, I felt I should share my experience. FYI, my problem is fixed, NOW.
Go to Settings;
mail, contacts, calendars
Scroll down to the bottom and turn off all calendars
Confirm that you'll delete the calendars (You gotta ensure you have backed up your device)
Then turn em' all back on, and accept the merge.
This fixed my problem.
I had some issues with itunes a while back, and I was fortunate enough to get to IM with an Apple rep... we did this type of thing with my contacts... I had it all setup wrong and I thought it was the cloud that had flaws. Well, when he walked me through those steps, my contacts problem was fixed, and I thought it might do the same trick for my calendars, and it worked.
I hope this helps. I know how frustrating it is when your smart device is a little too smart. Still a devout Apple patron.