Or maybe Curious Labs made some mistake in the code that didn't work well with Windows?! I had a brief conversation with them about a problem with Windows 2000. (Not enough disk space to render at this resolution, with 20GB free on the hard drive!) They mumbled something about virtual memory, and that was the end of that. I've only had that error once with Windows XP. I did a defrag (speed disk), and the problem ended. Ron