I could not get the fixes that were earlier suggested, but this worked for me. In the iPhone open Settings, Mail, Contacts, Calendars (below General). Scroll to the bottom under Calendars and there is an option for Time Zone Support, click that, then click time zone and set to your location (mine was set to Syndey Australia probably following a trip). I also have Time Zone Support on, but I'm not quite sure what that is. Anyway this worked for me and now my sync's for my calendars are working perfectly!