Hi again,
I did another quick test in the same scene but changed the colours of the gradient and the colours of the materials, plus the camera angle and a few other tweaks but nothing major. So the gradient material didn't crash with changes of colours within the gradient map, did you refer to other changes when it crashed?
I am still using the daily builds from 10 october because I did a test with the Corona 5 candidate 1 and I thought I had better results with the previous versions in terms of noise. I don't really know why.
Anyway, this is a quick test quite lowres but i thought i got nice results in terms of the caustics now.
I can upload this version of the max scene if it helps.
thanks,
cheers,
V