In microsoft windows products up until windows 95, when you rightclicked, the rightclick window would be drawn with its upper left corner on the mouse point, unless there wasn't room for it due to the edge of the screen. In that case, it would be pushed up or left until it fit. So for example, if you rightclick very near the lower right corner, the context menu would be flush against the corner.
However, in Windows 98
and Windows 2000
this behavior was changed so that if the window would have been pushed before, now it will be flipped so the mouse point is at one of the other corners. So if you click in the LR, the menu will extend up and left from the point of the mouse. This caused you to constantly subconsciously have to figure out of you are near enough to the bottom of the screen to cause this flip.
, this behavior has been changed again - it's back to the way it was in windows 95
, except now the window flips left. However, this is not an issue, since menu selections don't change horizontally anyway. So if you're near the bottom of the screen, the menu will be flush against the bottom. This is good.
The current windows behavior for this is bad because the threshold for when the menu would start flipping is hard to predict. So if you want to move quickly to a selection, whether you have to move up or down can depend on just 1 pixel
of difference. If it still behaved the way it did in Windows 95
, you would always be able to predict if you were going at least up or down.
In Windows 95, the location where the menu will appear is continuous as you move the mouse, and that's nice. In later versions it is discontinuous, which means that your natural attempts to optimize repetitive behavior will constantly force you to try to figure out whether the right click window is going to pop up or down.