Version:            (using KDE KDE 3.5.1)
Installed from:    Gentoo Packages
OS:                Linux

The scrollbar should be at the edge of the screen when a window is maximized (with the "Allow moving and resizing of maximized windows" unchecked), not ~3 px from the edge. This allows it to be more easily reached as one can just "throw" the mouse at the edge of the screen (much in the save way that the close button should be at the far right (or left) corner of the screen so its clicked when you have the mouse at the uppermost pixel)
At the moment one has to either aim at it or go to the far right and then a few px left again.

What i believe is done on Windows is that even though the scrollbar is visually ~2px from the edge, you are still able to scroll when you have the mouse at the edge.