I have a very simple model with two objects: Name and Category. One Name can be in many Categories (it's one way relationship). I'm trying to create 8 Categories every with 8 Names. Example code:

        NSMutableArray *localArray = [NSMutableArray arrayWithObjects:
                                  [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                   @"g1", @"Name",
                                   @"g1", @"Icon",
                                   [NSNumber numberWithBool:YES] , @"Male",
                                   nil],
                                  [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                   @"g2", @"Name",
                                   @"g2", @"Icon",
                                   [NSNumber numberWithBool:YES] , @"Male",
                                   nil],
                                  [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                   @"g3", @"Name",
                                   @"g3", @"Icon",
                                   [NSNumber numberWithBool:YES] , @"Male",
                                   nil],
                                  [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                   @"g4", @"Name",
                                   @"g4", @"Icon",
                                   [NSNumber numberWithBool:YES] , @"Male",
                                   nil],
                                  [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                   @"g5", @"Name",
                                   @"g5", @"Icon",
                                   [NSNumber numberWithBool:YES] , @"Male",
                                   nil],
                                  [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                   @"g6", @"Name",
                                   @"g6", @"Icon",
                                   [NSNumber numberWithBool:YES] , @"Male",
                                   nil],
                                  [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                   @"g7", @"Name",
                                   @"g7", @"Icon",
                                   [NSNumber numberWithBool:YES] , @"Male",
                                   nil],
                                  [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                   @"g8", @"Name",
                                   @"g8", @"Icon",
                                   [NSNumber numberWithBool:YES] , @"Male",
                                   nil],
                                  nil];
    NSMutableArray *localArray2 = [NSMutableArray arrayWithObjects:
                                   [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                    @"Test1", @"Name",
                                    nil],
                                   [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                    @"Test2", @"Name",
                                    nil],
                                   [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                    @"Test3", @"Name",
                                    nil],
                                   [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                    @"Test4", @"Name",
                                    nil],
                                   [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                    @"Test5", @"Name",
                                    nil],
                                   [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                    @"Test6", @"Name",
                                    nil],
                                   [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                    @"Test7", @"Name",
                                    nil],
                                   [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                    @"Test8", @"Name",
                                    nil],
                                   nil];

    NSError *error;
    NSManagedObjectContext *moc = [(AppDelegate *)[[UIApplication sharedApplication] delegate] managedObjectContext];
    for(NSMutableDictionary *item in localArray) {
        NSManagedObject *category = [NSEntityDescription insertNewObjectForEntityForName:@"Category" inManagedObjectContext:managedObjectContext];
        [category setValue:[item objectForKey:@"Name"] forKey:@"Name"];
        [category setValue:[item objectForKey:@"Icon"] forKey:@"Icon"];
        [category setValue:[item objectForKey:@"Male"] forKey:@"Male"];
        for(NSMutableDictionary *item2 in localArray2) {
            NSManagedObject *name = [NSEntityDescription insertNewObjectForEntityForName:@"Name" inManagedObjectContext:managedObjectContext];
            [name setValue:[item2 objectForKey:@"Name"] forKey:@"Name"];
            [[name mutableSetValueForKey:@"CategoryRelationship"] addObject:category];
        }
    }
    [moc save:&error];

And here's a problem - i've checked that 8 Categories are saved, 64 Names are saved but only 8 from all Names are connected with any category. So when i query for Names in Categories [NSPredicate predicateWithFormat:@"CategoryRelationship.@count != 0"] there are 8 elements and when [NSPredicate predicateWithFormat:@"CategoryRelationship.@count = 0"] there are 56 elements. What is going one here?