Has anyone seen this problem?

In 2D,
r = 4, -1<x<3 does not display a slice of a circle, although
r^2 = 25, -1<x<3 works.

And in 3D,
r = 4 + 0*phi, -1<z<3 cuts off the bottom of the sphere, but doesn't
display a slice of the sphere.

I'm using Graphing Calculator 3.5.

Stan Cohen