I’m looking out for our calendar users this morning suffering from iOS 4 woes. For those dealing with scrambled or blank events in the list view, iTWire quickly details how the problem may be remedied:
Some solutions are showing up. Our calendar is hosted by Google and uses CalDAV to sync to the iPhone. By going into the account settings and deselecting the “Birthdays” calendars the List View is correctly refreshed. So, it would seem that one of the default calendars created by the operating system is to blame.
Neowin suggests that entries older than six months old are also to blame, so you should archive older entries if you can. Though if you’re connected to an Exchange server, there’s not much you can do to fix the issue other than submit your standard Apple feedback report.