Are you viewing in "full screen" mode?
A few of the posts I've seen regarding screen size lead me to believe that some folks may not be aware of the full screen option on their pc. When I was new to the wonderful world of computers, it took me quite a while to stumble upon this very convenient feature.
When I surf this site I always punch the F11 key on my keyboard. That hides the taskbar and minimizes the toolbar, dramatically increasing the viewing area on my monitor.
My OS is IE and Win98SE. I don't know the shortcut for other operating systems.