Just a hint for anybody.( It may be better in more recent versions of Carrara?)

When bouncing the balls off the plane, they tend to sink half way in--which looks a bit odd---I gather the solution is to have an invisible duplicate of the plane just above the original and use that as the target for the bouncing items.

Brian
(And I have given up on trying to find my original .car file---I am really upset!)

bwtr