There are definetly certain things that cause the errors, but I don't get them that often. As far as booleans go, I would avoid them as much as possible; Carrara actually alters the polygons (as opposed to Bryce, which uses raytracing to define booleans), even the best of algorithms for doing this can have bugs; though I will say I'm certain Carrara's could be much bettter. We should know what Adobe plans to do with Carrara in the next few weeks - hopefully they will put out some patches. Brian P. Retford Carrara Extensions www.losthorizonsoftware.com