Thanks. I'm going to download 4.01 tonight and try it. I'm not at the machine right now, so I don't know the size of the objects. the polygon count is up there - between 20,000 and 40,000. I haven't let it set for a long time, I can try that too. What normally happens, though, is that the box for Object Presets comes up, showing the Boolean object collection. It tries to show the first one in the preview box, and freezes after the first few pixels are drawn. I have a Windows machine sitting next to my iMac, but Bryce seems to run slower on it (it's a 600 mHz PIII with 128 - Ok Mac guys, let's not get into it ;-), but I may have to see if I get the same problem on it.