Hi Val,

re:
> I think I might have found a bug. If I make a box (or any solid) and then scale it then go
> to undo It solid disappears instead of returning to it's initial state.

You've definitely found a bug, thank you for reporting it! Looks like something going wrong with undo and Transform commands that show the original object in wireframe at some point during the command.

Tomorrow I will dig into it in more detail.

Thanks, - Michael