Samsung devices often need a factory reset after a firmware update. This clears out any bits of the old code that are hanging round in the system cache and confusing it. Normal operation should be restored afterwards. Don't forget to back up your content and make sure your contacts and calendar are fully sync'd first. It's also a good idea to make a note of your homescreen layouts.
It may also help to restart the phone before doing the update, just to clear out appp caches and running processes, though it's too late for that in this case.
