I goofed during the Open Day - should have brought my older son and had him play with Alice there. This now has been remedied. I installed both Alice and Storytelling Alice at home.
Alice installed just fine and ran well. There are some quirks with the image of the scene - occasionally the main window just loses the feed. But other than that - works like magic.
Storytelling Alice showed a runtime error. I suspect it did not like Vista.
At any rate, the kid is having fun moving trees and making mechanical spiders jump.
It occurs to me, that this is a nice prelude before getting him started on Lego Mindstorms.