I fixed this error in LengthUnit_zh_TW.properties, but it was the only wrong file.
In all cases, surface texts shouldn't be based on [font=courier new]centimerUnit[/font] property but on [font=courier new]squareMeterUnit[/font] or [font=courier new]squareFootUnit[/font] properties according to the current unit set in preferences, and to avoid wondering how to format surface texts, programs should use [font=courier new]getAreaFormatWithUnit[/font] in [font=courier new]LengthUnit[/font] class, like in the PlanComponent class.
Dorin, did you use the same way?