I was playing with big models, 500K, 800K polygons and strange things happened.
First I imported a 470K mesh and Poser loaded and rendered it without any problem.
Fine, next to complicated a little more I imported another model with 500,000 polygons, Poser loaded without any problem, but when I tried to render Poser freeze, CTL-ALT-DEL.
Ok, too much polygons, so I opened again the scene and deleted the first model and when tried to render Poser stop breathing, CTL-ALT-DEL again.
Two similar in size models, but rendered without problem and the other killed Poser, something must be wrong with the second model, what?
I replaced the second model by another 500K one and the result was the same, death.
The scene was nothing, neither the ground, only the model. I replaced the 500K mesh by a decimated 250K version and death again, tried a 100K version and halloween again, only a 50K version was able to render, meantime the first 500K model never had a problem.
Something must be wrong with the killer model, but the assasin has no problems, all is ok, no degenerated vertives, faces, NaN vertices values, all is ok, but kills Poser.
I started with the 125K version and cut in two pieces, the smaller part was able to render, the bigger no. I continue cuting the mesh trying to find where is the problem until all parts were able to render, so I was unable to find the wrong part.
When I tried to render all the parts together it rendered fine, so I began the inverse process welding part with part trying to find when the problem appeared again, but it doesn't happen and I had again a 125K model that was able to render.
The cut and glued model had exactly the same number of vertices and faces as the original, no vertice or face data was changed in the process, both meshes are equal, but one renders and the other kills Poser.
The models have no texture coordinates and I tried Poser 4 and Poser 6 and both gave the same behaviour and the problem only happens when Poser start to render.
But when doesn't die it renders without any problem with no assasin models, I renderd 1,000,000 polygons including Vicky4 with Poser4 in a relative fast rendering.
It's a mystery for me the assasin models, I have no explanation.....

I didn't read all of the above, but check the bad model for polygons of greater than 4 sides.  I thought I read here that it didn't matter anymore, but in the old days poser preferred quads.

The model has only triargles or quads depending on the version, I have checked for any possible problems with many tools and found nothing.
The most strange is that the problem is preserved when the mesh is reduced in size.

It's likely to be a problem with some of the other information in the model, grouping, materials, UVs, normals, smoothing, etc.
It's also possible that ngons, or degenerate polygons might be the cause.

The models beside the number of polygons are very simple, only one group, only one material, no normal neither uv mapping present in the obj file and the faces are are only triangles or quads and nothing is wrong and the reconstructed mesh that is able to render has exactly the number of faces and vertices.

When you say "no UV mapping", do you mean there are no "vt" lines in the OBJ?

Poser doesn't like models without "vt" lines.

OH GEEZ OH PETE - DON'T SAY STUFF LIKE THAT!
I have been working on a HIGHLY detailed hovercar model (see my gallery) that I plan on Poserfieing and hopefully either sell for much needed supplimental income - or give away because it's my first major project! You guys are spooking the habeegies outta me! lol.
It's subdivision and I'm doing it in WINGS3d.

Quote - When you say "no UV mapping", do you mean there are no "vt" lines in the OBJ?

Poser doesn't like models without "vt" lines.

No UV at all, no vt entries no uv indexes in face entries.
One more detail, as the models were huge in dimensions I first imported them in Poser, scalled down to something normal and exported again to be used in the scene, so the mesh was processed and exported by Poser first. I never tryied to render the original mesh.

THe sliced and glued mesh that works is the same as the original, the only thing that have changed is the vertices and face order, so the only possible explanation is that Poser is sensitive to the face or vertices order that appears in the file, it makes no sense, but is only sensible for rendering, importing, exporting, scalling, rotating, moving, grouping, spawning, works fine without any problem.