Something else occured to me. Every time I've encountered texture problems with subdivision it was while doing so on a low poly figure. Stands to reason that the mesh shrinks a bit when subdivided and less so as the resolution increases. As you know, if you subdivide a cube it becomes a rough sphere (unless edges are set to hard), additional steps aren't as drastic of a change. Just figured I'd mention that, subdivision will be more forgiving to a higher base resolution seems like. Less of a shock. You've probably noticed the effect that subdivision in wings has on mesh UVs that were done on a low resolution mesh, once you subdivide the existing UV edges become more rigid and angular, it sometimes results in a bit of texture stretching or distortion. I know very little about the inner workings of Poser subdivision and how it handles UVs under such conditions but the mesh does contract or shrink. Might be the problem.