I plugged my iPad into my pc and decided to update to 4.2. After the update, none of my downloaded apps are working. When I select it, the screen flashes the app, but then returns back to the home screen. I see them all in the multi-task bar though. What's going on?! Did my iPad never finish updating or syncing? Please help. I've only had my iPad for a day and it's ruining my experience. Thanks.