Projected pointer position isn't recalculated when pointer doesn't move

[canadaduane]

In the pointer-events example, there is a set of 4 polygons rotating about the Y axis. If you hover the mouse pointer over a polygon and then click many times (without moving the pointer) the 3D projected position of the mouse pointer is calculated incorrectly. I believe it may be because it assumes that if the mouse pointer hasn't moved, some part of the calculation can be cached?