I need to show a popover when selecting an item in a NSListView; whis works just fine, but I cannot get my image to show.

This is the controller for the popover:

    public ImagePopoverController (NSImageView imageview) : base ("ImagePopover", NSBundle.MainBundle)
    {
        Initialize ();
        ArticleViewer = imageview;
    }

This is my override for the table delegate:

    public override void SelectionDidChange(NSNotification notification)
    {        
        var Table = notification.Object as NSTableView;

        TableProduct SelectedProduct = DataSource.Products[(int)Table.SelectedRow];

        if (File.Exists(String.Format("cache/{0}.png", SelectedProduct.SKU)))
        {
            imageView.Image = new NSImage(String.Format("cache/{0}.png", SelectedProduct.SKU));
        }
        ImagePopover.Show(new RectangleF(0, 0, 0, 0), View.View, NSRectEdge.MinYEdge);
    }

The popover shows fine, but I cannot get the image to load.