List problems

We're having some trouble with the list objects and the ListVisualization class.

The remove methods in ListVisualization shrink the visualization, but do not make the removed objects invisible. (We're using 3D text numbers as the objects.)

Also, when a world using ListVisualization stops, the play button doesn't re-enable. Alice has to be restarted to replay the world or play another world.

We get a crash any time we do a remove from end operation on a list.

We see the same behavior on PCs and Macs.

Has anyone else experienced this? Any workarounds?