I'll be a monkey's uncle !
I somehow had 'structure lock' on the Stepper+ worksheet. This basically freezes the page - unable to move, resize, ... !
It is back to normal with this update. You should be able to move about, resize, change tab/worksheet and all that fun stuff.
Not certain why I couldn't find this 'bug' earlier as it is locked/unlocked separately from the rest of protection scheme in Excel ...
OXcalculator - Bill of Material and Cost calculator v1b006 (xls + ods)
OXcalculator - Your computer figures out the parts you need to build your OX by giving it X, Y & Z