Upgrade to iPhone 3.0 sdk and now simulator shows blank screen

Question

I have an iPhone app that uses an UITabBarController, which contains two UINavigationControllers, each of which in turn contains one or more TableViewControllers (actually,

Answer 1

It appears you have to save the new interface before running. I have never developed for IPhone before and finally figured out why i was getting a white screen. Seems like it should save automatically before running but apparently it doesn't.