Surface Area Discrepancies

We have noticed a discrepancy lately when measuring surface area from a reference file inside a model.  The area in the reference file (when opened directly) measures differently than when we measure it as a reference in a model. 

We have verified that the design files have the same units, decimal position, etc.  The only significant difference is that the model scale is at 1:100.  The difference between the measurement in the reference file and the model is a matter of 1.2295m2.  To complicate matters a bit more, when I copy the shape from the reference into the model , its area is the same as the original reference file, and not the measurement as when it is in the model.

Does anyone have any suggestions?  Both files are 2D, Connect v13