Sorry David. Can't help with that one, as I've been getting the same trouble myself. I don't think it's any secret though, and I'm sure someone out there will help us out.

Hi David, try this. Make any shape, a box, a ball . Anything. Group it, as you normally do,
click 'Play Physics simulation' and the blue Control panel will appear. Place your cursor, which will now look like a 'hand', on the object and right click. Pick an option from the pop-up box,
then left click your object. That OK?