Because many models are imported into Vue, it's important to understand how Vue handles the smoothing of them, and to recognize when objects are not smoothed properly. Hopefully this helps.
Smoothing Notes
Above there are two different ways to 'FIX' smoothing, but this trick may be the best one yet.
Separate your models into groups of polys you want smoothed by setting a unique material for each group before importing.
Then after importing, edit the mesh and then
1) SPLIT on Materials THEN; TURN OFF smoothing
Turning off smoothing will unweld co-incident vertices of the material group polys that are split. Press OK and refresh to make sure it works.
2) Then edit the newly created group and turn smoothing back ON and press OK.
3) Now you can go back into the Polygon Mesh options dialog and press WELD to put everything back together.