faceboxHtml includes a default url for the close label img. In cases where the path of closeImage is overridden on init, the initial html loaded into the page contains the default path. The override is eventually honored, but not before a request for the default url fires, leading to a 404.

I have a simple fix on my fork--the default html simply doesn't include the src attribute on the close_label img. In all cases--whether the path is overridden or not--the correct image is attached at runtime.

The commit is at http://github.com/lukeman/facebox/commit/61a11bcaabfe7514efcde5f23949e26a3a48d699 and I've sent a pull request.