When i finally made a rather difficult scene in Bryce 5 with lots of imported objects & really lot of work in Bryce itself i tried to animate it. The result was that almost every imported object and lots of negative objects went under the virtual floor, even if they where grouped. I don't know if this is a Bryce 5 bug or some kind of my mistake, but i experiment a little with Bryce 4 too & i got the same results. Sometimes i had this when i copy & paste imported objects from one Bryce file to another and press 'Undo'. The whole scene seems to explode. Can anyone help?