banner.module and private images

Hi there!

I decided to give banner.module a try. On the site in question, file
download will be set to private. This does not make much sense for
banners, but I can live with the overhead (I think, if you know a
workaround, let me know).
What worries me is that it does not seem to work. The banner seems to be
loaded when the page is built up by the browser, but then disappears.

Any hints?

Cheers,
        Gerhard