Piweb Flatness

[[Ja...]]

I am measuring the flatness of several plains. The first two are the same size and have nearly the same measurement result. I go into the flatness characteristic, select 1500 error magnification and open Piweb form plot. The first one looks really good and in the bottom right-hand corner says 1500:1. Above that it says 1.000 minch. I think that's supposed to be inch. The second one also says 1500:1 but above that it says .100 minch and looks more severe. I think that's right, but the first one is wrong. It's like that no matter what I do. I have recreated the flatness characteristics and still the same thing depending on which plane I select. What could it be about that first plane? Both flatness results are within .0001" of each other. 

[[Ja...]]

Here are some screen shots. Is there anything else you would like to see?