Why is Poser creating extra edges on import. This seems to be screwing up the UVW Map I've applied.

 I can't determine much from the picture.  The preview and render don't seem
to be the same object in either case, and you don't say whether the radio-receiver
thing is supposed to be part of the rounded-rectangle thing.

Still, one problem is fairly clear.   Poser doesn't like "fans" of narrow triangles.  
If you rebuild the rounded-rectangle thing with a more uniform rectangular mesh,
Poser will like it better.

Poser doesn't like "fans" of narrow triangles.

Yes that is clear. I'm not building any triangles, its why I posted the Max model as well so you can see Poser is adding something during the import or Max isn't showing me something in the preview.

The preview and render don't seem to be the same object in either case,

They are exactly the same object in each case.

What does the rounded-rectangle-thing look like in Poser, in wireframe display?

Are your polys double sided?

Quote - Are your polys double sided?

No. Why should they be?

They shouldn't be.  But double-sided polys are a common problem
when Poser dislikes a mesh that works nicely in other apps.

what you have in 3dsmax is an n-gon,that is a face with more than 4 verts,you need to manually makes those edges using the cut or connect tools or max will have to guess on export where to create the new edges,
you want the mesh looking like the one ockham made,(except no horizontal edges should be required)
the texture distortion is caused by the fanning triangles

Fans can work in Poser if you UNWELD the polygon s that make it up.   Ockhams mesh is better though .

Thank you all.

That's good!

Incidentally, Poser's earlier versions handled many-sided polygons much better.
And some of the earlier standard Poser models have extreme polygons, which 6 and 7
choke on.  The Girls Pigtails hair mesh, for instance, has a non-planar
front face with about 100 vertices.  P4 handled this, but P6 and P7 don't.

Maybe Smith Microsystems will improve on that in Poser 8. Unless of course yet another company buys Poser in the mean time. ;)

Smith might actually do it.  In this latest SR they've fixed a number
of long-standing deep problems, which e-frontier didn't touch.

Very interesting! I had the same problem with objects once in a while. I knew about the n-gons, but didn't know that Poser doesn't like fanning triangles. What about a circle (top/bottom of a cyl), or the outside of a circle: A cabin window of a ship. Is it possible to avoid both fanning triangles and n-gons there???