Why is it that sometimes I can move the dials on the Parameters tab, and sometimes I can't?  Am I (probably) doing something really stupid?

  ~ Russ  

Double-click in the dial to see if limits have been set.

It is so strange...  I quit PP2014, then restarted it and was able to move the dials.  Then, as I was messing around with the object I was posing (a "prop" shirt) it suddenly quit working again.

There does not seem to be any reason, or pattern, that I can detect.

If someone knows what can be done to reactivate the dials without restarting Poser, it would sure be appreciated.

  ~ Russ  

A prop shirt?

Even though you loaded it from a props library, it may be a .cr2, i.e. a conforming figure; and if you have "Include morphs when conforming" enabled on the shirt, spinning dials driven by this feature won't do anything. But dials in the clothing that have no counterpart in the figure that the shirt's conformed to will have an effect. 

So is your problem that spinning the dials changes the value but has no effect, or that the value doesn't change?

Try disbaling "Include morphs when conforming" and see what happens.

This has been an issue since the last version.  SM & I haven't been able to nail down a cause.  It appears to be totally random.

Yes, that happens to to me on very rare occasions.  Usually in big scenes.  I am on a mac.  one time when it happened I had HW shading turned on. I turned it off and poser became more responsive, but the dials didn't recover until I restarted poser.