Compiling against iOS SDKS
<p>I have a question regarding compiling against SDK's, which I thought I understood until yesterday. </p>

<p>I have an iPhone app, which the version compiled against SDK v3.2 and running on an iPhone emulator runnning version 4 works fine, but when I recompile the app against SDK 4 the interface starts to mess up.</p>

<p>I thought when you write an app against an SDK/Frameworks like iOS or the Android SDK's, the code you write gets compiles into an app (with any added libs), and then get excecuted on the system. The sdk being present on the dev machine for the purpose of the app being able to compile (and run compile time checks) but not actually compiled into the app code. </p>

<p>What I dont understand is that if this is the way it works, how can just compiling against a newer version of the SDK break the app (bearing in mind whatever version it is compiled against it is still running on iOS version 4) as how is it not still the same compiled app.</p>

<p>Obviously I am missing something here!</p>

<p>Thanks for any pointers</p>
