iPhone SDK 3.0 problems

I’ve recently updated to SDK 3.0 for the iPhone. My app and the SDL demo
apps still compile and run fine when building for SDK 2.2.1. However when I
build either of these for iPhone Simulator or iPhone Device 3.0 the app just
displays the loading screen but doesn’t update the screen beyond that. The
apps are still running fine ‘behind the scenes’ but it’s as if the
SDL_Present isn’t working and the frame buffer never gets flipped. I’ve
stepped into this in the debugger and it looks like it’s all being called ok
and there aren’t any SDL or GL errors.

Anyone had any luck with SDK 3.0?