You must be using the auto calculator, the on screen popup keypad. It does require the 0, or some digit, before the decimal. Thats not a wizard problem, its how the keypad works.
There is a a known bug that causes the 'last screen' button to fail to load all the wizards graphics if its the first thing called after bootup of mach. If you select the wizard from the menu it works fine. Brian knows about the bug, I guess he hasnt fixed it yet.