MPMediaLibraryDidChangeNotification called twice?

Question

My app uses the iPodMusicPlayer and, when suspended, the user might go out and make changes in Apple's Music App, for example creating or modifying a Playlist, then return to my App.

I receive the expected MPMediaLibraryDidChangeNotification, which is fine and I deal with it updating my references etc., but I receive a second MPMediaLibraryDidChangeNotification about 2 minutes later which I really don't need.

Any ideas on avoiding this second notification?

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(notification_iPodLibraryDidChange:) name: MPMediaLibraryDidChangeNotification object:nil];

[[MPMediaLibrary defaultMediaLibrary] beginGeneratingLibraryChangeNotifications];

Answer 1

if( !self.lastModifiedDate )        self.lastModifiedDate = [[NSDate alloc] init];
if( [self.lastModifiedDate compare:[[MPMediaLibrary defaultMediaLibrary] lastModifiedDate]] == NSOrderedSame )  return;
self.lastModifiedDate = [[MPMediaLibrary defaultMediaLibrary] lastModifiedDate];

The above lines in my notification handler method deal with the extra call. Still no idea why I'm getting it.