When importing a model into WED, the Z position is altered so that the very bottom vertex is at the 0 position, even when manually typing a position in with WED.
To reproduce:
1. Create a sphere model in MED (use the primitives if needed), center it on all 3 axes, and save it. No need to texture it.
2. Load the model in WED and set it's position to 0, 0, 0.
The very bottom of the model does not match what was depicted in MED. Try adjusting the centering effect in MED and reimport and see the effect. In all cases, the X and Y axes work fine but the Z position always has the same scenario: the bottommost vertex takes the 0 Z position. Like the X and Y axes, the Z axis should behave the same. It makes it tricky to position models.