I'm officially an idiot. Yes, I hadn't set it in the render settings. I didn't anticipate that there would be such a setting, because why would you apply a displacement map at all if you didn't want to use displacement maps? But such is the way of the world. Thanks for the help!

Thanks for the comments. Alas, they haven't helped! It's nothing to do with textures (this happens when I remove them, too). And it's not just Firefly. It happens when I use the Poser 4 renderer too (I'm using Poser 6, by the way). It's nothing to do with raytracing either because I haven't got that on. Anasta, I don't have an Irridance Caching option, but fiddling with the others you mention doesn't seem to help.

Incredibly, though, the Sketch render options do not have the ink stain! Which is completely useless for what I'm trying to do. Ah well...

But if you think your image is terrible, why post it...?

Thank you both enormously. I was convinced that this should be possible, but the one thing I didn't know was:

Quote - 2. Turn on IK for both hands. If you don't, you can't parent them.

I wanted to parent the hands to the prop, but saw "Change Parent" greyed out so it seemed completely impossible. I didn't know that turning the IK chains on first would change this.

Everything seems much easier now. I'm using Poser 6 so hopefully that crashing won't happen (although I'm used to it by now, if it does...). Thanks again!