Comment 69 for bug 197781

(In reply to comment #51)

> document.loadOverlay(OverlayLoader.queue[0][0], null);
...
> setTimeout('OverlayLoader.load()', 100);

Using a timeout here seems the very wrong way to go. Why don't you use an
observer as second argument to your loadOverlay() call? That way, you can
really know when the overlay is merged and pop another one from the queue.