I use(d) RDS and Carrara for modelling and rendering. Carrara has problems with both on my dual monitor Athlon system. It crashes when I render output as AVI files - so I must animate as an MOV and translate back to AVI with a post process. There also some bugs regarding cloaking in animations. The shader editor is outstanding in Carrara and is stable. ANyway I will try the Amapi modeller and see if it works. Thanks for the tip!