I've had this happen with a few items. I haven't tried to track down what the issue is. For some reason, the preview image of a material, like a transmap, will display the 2d diffuse image.

It happens rarely to me, usually with hairs. But, that's probably because I just notice it there, more, since I frequently try to tweak hair materials.

As I said, I haven't looked into it. As long as they image file appears to be named correctly, it should render fine in my experience with this bug. It might be worth taking a look at the object file, itself, to see if it has some strange weirdness going on. (Shouldn't, though.) The same is true for the .cr2, of course. And, of course, check the directory to be sure there's no .mtl file in the object's directory present, causing confusion.

You said you're using the .hr2 file type. I don't know much about those, but they shouldn't be much different from any other file-type Poser uses, I would guess. After reading over your post, again, I noticed you said it renders with the color map in place of the transmap. That's not my normal experience when this occurs to me. It sounds like something that can happen when there's a conflict, like when a .mtl file is present in the same directory as its object file, forcing materials to be loaded despite what a CR2 or anything else wants to say about it. You'll have to look at the hr2 file.

Alternatively, you might try renaming all the 2d textures and/or relocating them, then saving the hair file under a new name to see if that clears it up.