A quick follow up. Just to say I had done so for certain, I submitted a bug report  to CP about Poser flipping between the Properties and Parameters tabs when you use IK. The response I got back said that it's not a bug, but an enchancement.

Very interesting. I've never seen  anyone enchance an annoyance before, but then my experience in software development is very limited. I know what I like though. And what I don't.