Ubuntu :: Unable To Select A Window Border

On my system (Ubuntu 9.x -> 10.x) I have always had the problem of not being able to select the edges of a window in order to change the window size. It seems that the 'hot' zone, which defines the window border selection area, is only 1 pixel wide. I find it very difficult to position the mouse pointer over this zone. Even if I am successful (which usually takes more than 20 tries), as soon as I begin to depress the mouse button, the merest movement causes the pointer to move off the 'hot' zone - and selection fails. The only work-around I have found is to select a corner point of a window -which seems much less sensitive - and then drag the window border in either a vertical or horizontal direction, rather than diagonally. But this is counter-intuitive and unsatisfactory.