Bring up the config window and set azimuth to about
133. The grey wireframe appears in the rear corner of
the cube, though it should be occluded.
Now hit "replot". First of all, the plot becomes smaller.
(Why?) Then, when you rotate it, it breaks up into little
squares or pieces of broken glass as you rotate it,
though it reverts to a correct plot after you stop
rotating. This doesn't happen in the original plot.
Maxima 5.9.0 gcl 2.5.0 Windows 2000 mingw Athlon