@jaytreiman 

Thanks, I thought I had up to date drivers but didn't.   Updating the video driver fixed the problem.  thanks again

@jaytreiman

Thank you for the input.  I"m using a daul core intel processor (La975) 4 GB of memory and a Radeon X1300 video card.   The software is the first 3D example in the help section for plot3D.  I'm using Windows XP Sr 3.   I'm wondering if this is a windows xp problem.  

Knut