I was experiencing the same types of problems reported on this list with Nvidia 1.0-28. I have just installed the newest version of the Nvidia drivers and all my previous problems have gone away. Info: Nvidia 1.0-2960 vtk3.2 XFree86-4 Debian Testing Linux 2.4.18-686 nVidia Riva TnT2 So, I think Nvidia fixed the problem. -- Samson