I have created another version, with a slightly different approach to the positioning. It shuold be ok now in all browsers you test in :)
http://goba.hu/phpnetfooter.html
Copyright link is working now, but NS7.02 shows the gray background only until the middle of the copyright line vertically, from the top. anything below is white background.
Huh. According to the rules, the "this mirror" text should define the height of the gray background. I don't know what might be problematic for NS 7.02...
Goba