>I don't see backgrounf image in FireFox 1.0.7 either even after clearing cache and browser restart. Here the reference to the image in question copied from the page source code

The base href does not kick in in Firefox. That's the only think I could see presently. That is needed as all images in articles won't work either. I don't know if that could be caused by a security in place or if it is simply not supported.