db3tech, Emmanuel:

DB, that's an interesting observation. I didn't test it as methodically as you did, but it rings a bell. I sometimes get "half" renders, where the rendering stops halfway the picture. Also, when rendering this picture in high quality (size 400x300 pixels) it took AGES (as in "several hours") to complete. Maybe that was because I used around 25 lights, but the rest of the scene was very simple: just the lady and the tree (OK, that's a complex model) and a wall with a small texture.

If I have more time, I will certainly try to do some more testing in the next days.

Hans