I have a smart key-board, and all shortcut/function keys work perfectly with screensaver in window mode and full screen , 98se/2K and also on my me and 95 machines - one thing u can look at is make sure ur key is still pointing to the funtion like
www.yahoo.com or whatever u want it to function as or it wont work no-matter what
i did have to reset my key functions (predefine) them after installing the saver .now all works fine.