Hi Michael,
I imported it ok into max, xsi and, houdini
In houdini the sphere is imported with no seams, but the other objects look identical to the xsi import with disconnected edges.
As you can see below(xsi screens) there are a lot of seams in the sphere especially at the poles(blue lines depict open edges).
I exported a similar polysphere to fbx format from max, and a nurbs sphere from xsi ; both do not generate disconnected edges.( i have attached both objects )

sorry for the quality of the render..bad gif compression