Problems with OpenGL example

Hi!

If I try the ICOSAHEDRON-VIEWER example that comes with LispWorks (LWW
5.0), I reproducibly get a window which displays a tail of white
squares following the mouse.  See here:

  http://miles.agharta.de/opengl.png

This strange effect goes away if I hide or minimize the window and
then show it again, but - as I said - it is reproducible.

Furthermore, and even more annoying, if I try to actually move the
Icosahedron with the mouse, it takes more than ten seconds (!) until
it actually moves.  Inbetween, the mouse pointer becomes an hour glass
from time to time, but that's about it.  CPU usage isn't very high.

If I use the :DOUBLE-BUFFERED-P NIL option, movement is without any
time lag, though, and the white squares also aren't there.  However,
the display flickers which I guess is to be expected without
buffering.

Does anyone else see this?  What can I do to make this work correctly?

Thanks,
Edi.