title: NSXMLParserDelegate and iPhone SDK 3.1.X
body: <p>I have an app on the store which was built for 3.1.2, but which was crashing under 4.0GM. I've fixed the crash problem using Xcode 3.2.3, but was also getting warnings that such-and-such class did not implement NSXMLParserDelegate. I added  to the headers and everything seemed fine. I've now submitted the app and it's waiting for review. This latest version was compiled with base SDK of 4.0, and a deployment target of 3.1.2.</p>
  
  <p>The problem I have is that this morning I opened up the project in Xcode 3.2.2, and when building against base SDK of 3.1.2, I'm getting compile errors saying that NSXMLParserDelegate does not exist. Does this mean my app that is waiting for review is going to crash under 3.1.2 devices? This is strange, because my beta testers who are using 3.1.3 and I think 3.1.2, said the app works fine. Shouldn't it crash if it can't compile against base SDK of 3.1.2?</p>
  
  <p>I think this should be ok to discuss in regards to the 4.0 NDA, as my problem is specific to 3.1.X.</p>