Question: contourplot3d and plot3d not showing contours

As stated, contourplot3d is not displaying contours. Even in the Maple Help examples the contours are not displayed in the help screen.

In this example:

contourplot3d(-5*x/(x^2+y^2+1), x = -3 .. 3, y = -3 .. 3, filledregions = true);

which is directly from Maple Help, the surface is plotted (with boxed axes), but no contours appear.

When I try

contourplot3d(-5*x/(x^2+y^2+1), x = -3 .. 3, y = -3 .. 3);

the plot shows nothing except boxed axes.

I've also tried

plot3d(-5*x/(x^2+y^2+1), x = -3 .. 3, y = -3 .. 3, contours=6);

and the surface shows but without countours. Furthermore, the Maple scripts that worked previously in earlier versions (showing contours via plot3d) now do not show contours in Maple 18. This occurs on both Win 7 and Win 8 laptops.

Thanks!