Two layout problems

hello,
The black layer that covers the screen when clicking on a thumbnail in slimbox doesnt work with some browsers. On some computers I saw that the black layer doesnt cover the whole screen and instead leaves 10cm om the screen uncovered (in my case to the right). Any ideas?

Second thing. Before the thumbnails are loaded and you only see white squares, the last pic to the right jumps out of my layout and gets a width of approx. 400px. It returns to normal width and jumps back in after finishing loading the actual thumbnail... pretty annoying and looks bad i have set a size for the ul.thumbs li already.

ideas??

thanks,
johan

Install firebug or webdeveloper extension to firefox and debug your css.