The Dapple-Grey Shire gave me a bit more of a problem. The HDRI lighting really amplifies any color artifacts in the white areas of a texture map. So- had a bit of small weird bluish and reddish spots in the white-only areas to remove using the Photoshop desaturate sponge.

I think that texture maps that look fine in Poser will need a more editing if they contain a lot of lighter areas. It's not a big problem- just something you will discover once you start doing HDR renders. Tiny defects will get amplified because the render method is so much more realistic looking...