Simulator app is no longer automatically updated

I have just upgraded to xcode 3.2.3. When I build and run the app, the simulator is not updated with the latest app build. Anyone knows why this has changed in this new release of xcode. If it is it's a shame as the env开发者_StackOverflow社区ironment is not as productive as it used to be, having to delete the app file each time in finder. Any ideas?

It works perfectly for me. Are you using different target for different iOS, are you sure that you are building and running the correct application? What part of the application is not updated or everything?