the developer used OS X, hence maybe these variables are in a more stable environment
in OS X than in windows.  I can usually finish a poser GI render, but it's mind-numbingly slow.
however, if ya jack up all the GI settings in Carrara to the max, that renderer is also real
slow.  that's why 3d users take various shortcuts when they're on a deadline.  it can look just
as good without all the settings at the max, if one follows the various lite/shadow/shader tips
posted here by baggins et al.