Mine too, having terrible problems with repeating events, when one event in the sequence gets modified, N9 just doesn't seem to pick up the changes

My setup is pretty different to your though, I'm not using Google, but DavMail as an intermediary to MS Exchange. But the same instance of DavMail talking to Thunderbird/Lightening handles repeating events fine, so I'm sure the issue is with the N9's CalDav implementation.