I use Carrara V 1.1 on a G3/350 (OS 8.6) & G3400 OS (9.0.4) and have no problems with crashes. The only problem is still with the final render, a pop-up comes up at the end of the render & says "there was an error...". I just close the pop-up & everything is OK. I've seen some info on some of the threads that there may be an extension conflict with ColorPicker &/or ATM. Try turning them off & see what happens. Note, ColorPicker is an older system extension that may have been installed with some other software. It's not part of OS 9.1 as far I know.