Problem with site

I didn't have this problem yesterday when I logged in, but today, I am getting the dreaded empty box with the little red "x" in the corner at the top of the page, doesn't happen on the homepage, just when I log in to the forum. The box is about 1 1/2 screen heights (Am running at 1280x768pixels). The scrolling txt still appears, and the top line of links seems offset (the homepage/uk club Pix line of links) The rest of the page then seems fine. Happens whenever I log into a post as well, seems to be to do with the forum banner. Is this a problem with the machine I am using, or the site. (Am only on the machine this morning, so afraid won't be able to tell you if it has been resolved)