Iphone sdk beta5: blank white screen

Question

I wrote a simple test app under beta 4, which broke this morning under beta 5. I can't figure it out.
The app simply creates a UIView that does a bunch of rectangle drawing on its main layer via drawRect callback.
When I run in beta 5, all I get is a blank white screen - both on the simulator and on the device. It's as if the view isn't created or something.
But, I can trace in the debugger and see all of my drawing code executed.
As a test I also tried setting the background color of the view. And of the owning UIWindow. I never saw color.
If I run the app in the simulator, without the debugger attached, sometimes (one in five?) it will run fine.
I don't see any errors in the console.
My main app continues to build and run fine. This is purely a nagging annoyance and a concern..
Anyone else experience something similar?

Answer 1

Fixed it.
Before there was IB for the iPhone, we had a slave over a hot cliprect and create the UI by old-world hand craftsmanship. My app still reflects those classic values, in that I created the window object directly:
self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
Apparently now the app does that automatically and then would slap it on top of mine right after creation. Since the original one had no content it was white. I was able to catch a very quick glimpse of mine (about 1 frame worth) before it was hidden one time which pinpointed the problem.
So removing the alloc for UIWindow in my code fixed the issue.