title: presentModalViewController not executing?
body: <p>I'm an experienced software developer (mostly C and C++ in embedded systems, Linux, and Qt for user interfaces).  I've recently made the jump to iPhone development and I've run into a confusing issue with UIViewController and presentModalViewController.  I'm trying to present a modal ABPeoplePickerNavigationController dialog but it's not appearing.</p>
  
  <p>My main application is controlled by an object called Controller, a subclass of NSObject.  I recently added a subclass of UIViewController called AddressBookController (both Controller and AddressBookController are declared in my NIB).</p>
  
  <p>I have this function in Controller which uses an IBOutlet to call a function in AddressBookController (Just a side note, I'm aware that passing 'sender' through is probably not correct--what's the correct way to call a function that's looking for (id)sender as a param?):</p>
  
  <pre><code>- (IBAction)addressPressed:(id)sender
  {
      [addressViewController showContactPicker:sender];
  }
  </code></pre>
  
  <p>Here's my interface declaration for AddressBookViewController:</p>
  
  <pre><code>#import &lt;UIKit/UIKit.h&gt;
  #import &lt;Foundation/Foundation.h&gt;
  #import &lt;AddressBook/AddressBook.h&gt;
  #import &lt;AddressBookUI/AddressBookUI.h&gt;
  
  @interface AddressBookViewController : UIViewController &lt;ABPeoplePickerNavigationControllerDelegate&gt;
  {
  }
  
  @end
  </code></pre>
  
  <p>The showContactPicker function in AddressBookController looks like this:</p>
  
  <pre><code>#import "AddressBookViewController.h"
  
  @implementation AddressBookViewController
  
  - (void) showContactPicker:(id)sender
  {
      ABPeoplePickerNavigationController *picker = [[ABPeoplePickerNavigationController alloc] init];
      picker.peoplePickerDelegate = self;
      [self presentModalViewController:picker animated:YES];
      [picker release];
  }
  
  ...
  </code></pre>
  
  <p>I've verified using the debugger that the [self presentModalViewController:picker animated:YES] is being called, but nothing appears on the screen and code execution just proceeds to [picker release].  Does anyone have any insight as to why this call isn't doing anything?  I'm not seeing any error messages, warnings, etc. as I run through this code.</p>
  
  <p>Thanks in advance!</p>