I don't care for the "mass_property_calculate automatic" config.pro option because of its global reach. EVERYTHING gets its mass calculated, whether you need it or not. This is especially annoying for assemblies that have a bunch of parts in them that don't have their mass set. You get stuck entering a mass property value for every one before the calculation can complete. I prefer to add a statement to the bottom of the pro/program file that automatically updates the mass properties for that specific part/assembly every time it is regenerated. If you want all new parts you create to keep their mass up to date, add this line to the pro/program statement in your start parts. And for those who are wondering, yes, pro/e is smart enough to change this line in the pro/program file if you rename/duplicate/create from this model.
MASSPROP PART <part name="> (or ASSEMBLY <assembly name=">) END MASSPROP
For more information on how this works, see the pro/e help documentation. In WF5, it's located under "Functional Areas / Program / Editing a Design / Mass Properties and INTERACT Statements / Updating Mass Properties When Geometry Changes"
One more thing. You aren't going to see the results from your analysis in the model tree under the PRO_MP_MASS column because that is not the name of the parameter in that feature. If you want to see the value of a feature level parameter, you need to add that specific parameter as its own column. You can easily do this by setting the tree columns type dropdown to "Feat Params" and then typing the name of the parameter you want to see in at the bottom where it says "Name". After entering the value, just click the >> arrow so it gets added to the list of active columns. If you are unsure of the parameter name, right click on the feature and choose "info". At the bottom of the page it will list the available parameters for that specific feature.
Something to keep in mind is that different features can each contain a parameter with the same name. The parameter is unique to that feature. This is very handy when you want to see a unique value from multiple features but you don't want a separate column for each one.