I suspect the modified Zone Stamp has the following fix in it:
In the original 2D Script you will see the following code start about 22 lines from the top:
area_form="" !*** format as set in the Preferences
rrr=request ("Area_dimension","",area_form)
room_area = str (area_form, ROOM_CALC_AREA)
Change the parameter in red as follows:
area_form="" !*** format as set in the Preferences
rrr=request ("Area_dimension","",area_form)
room_area = str (area_form, ROOM_AREA)
(Thanks to Viktor Bullain for showing me this one!)