When you upload a mesh object with analyzed physics, the physics shape for that object is displayed incorrectly when the object scale is below 0.5 meters on an axis.
Instead of the actual physics shape, a more simple convex hull is displayed. Physical interaction with the object proves that the displayed physics shape is not in effect.
I've attached two pictures:
  • One picture shows an imported mesh object with analyzed physics at
    <2, 2, 0.5>
    scale, with a default prim sphere (physics enabled) on the side.
  • The other picture shows the same object at
    <2, 2, 0.49>
    scale, with the physical prim sphere rolled into the gap.
This visual bug with displaying physics shape does not exist in TPVs like Firestorm, which can be used to see the actual physics shape.