iPhone: Missing symbols ; no view appears in multi-view app
Two bits of iPhone development info info that I just wasted substantial time banging my head on and want to promulgate so that others don't need to waste the time:

1) If you are writing a multi-view application where you are managing the views manually, your ViewController's "self.view" is nil until you assign something. This means that your screen will be blank on launch. If you're seeing this problem, just assign one of your views at the top of your ViewController's "-(void) loadView" method.

2) If you look in the console and see the following messages (or ones like them): "warning: Unable to read symbols for "/System/Library/Frameworks/OpenGLES.framework/OpenGLES" (file not found)" this is NOT something for you to worry about. It's a warning, not an error, and you should ignore it--it just means that you can't debug into the Apple-provided framework files (there are no debugging symbols there for the debugger to work with).