How to fix node insertion in NSTreeController on Leopard

gistfile1.m

#if MAC_OS_X_VERSION_MIN_REQUIRED <= MAC_OS_X_VERSION_10_5

- (void)didInsertNode:(NSTreeNode *)node;
{
    // See if model matches tree state. Leopard gets them out of sync, adding to the model rather than inserting
    id object = [node representedObject];
    NSIndexPath *indexPath = [node indexPath];
    NSUInteger index = [indexPath lastIndex];
    
    NSTreeNode *parent = [node parentNode];
    NSMutableArray *objects = [[parent representedObject] mutableArrayValueForKeyPath:
                               [self childrenKeyPathForNode:parent]];
    
    if ([objects objectAtIndex:index] != object)
    {
        // Correct model object's index
        [objects removeObjectIdenticalTo:object];
        [objects insertObject:object atIndex:index];
    }
}

- (void)insertObject:(id)object atArrangedObjectIndexPath:(NSIndexPath *)indexPath;
{
    [super insertObject:object atArrangedObjectIndexPath:indexPath];
    
    NSTreeNode *node = [[self arrangedObjects] descendantNodeAtIndexPath:indexPath];
    OBASSERT([node representedObject] == object);
    [self didInsertNode:node];
    
    // Correcting the model may have lost selection
    if ([self selectsInsertedObjects]) [self setSelectionIndexPath:indexPath];
}

- (void)moveNodes:(NSArray *)nodes toIndexPath:(NSIndexPath *)startingIndexPath;
{
    [super moveNodes:nodes toIndexPath:startingIndexPath];
    
    NSArray *selection = [self selectionIndexPaths];
    for (NSTreeNode *aNode in nodes)
    {
        [self didInsertNode:aNode];
    }
    [self setSelectionIndexPaths:selection];
}

#endif