Hip Y-Trans dial becomes locked at 250 frames into animation,    Spin the dial & it just reverts back to the locked value.  Several hundred frames later it becomes unlocked again.

-Figure not locked,

-Hip Object not locked,

-Dial’s parameter Minimum and Maximum settings don’t affect the locked value.  (it stays at the locked value even when the Min/Max range does NOT include the locked value.)

-No IK, Point-At, Auto-Balance, or other Auto functions on - AFAIK.

-Rebooting & Reloading has no effect.

-Importing the PZZ into a new scene has no effect

What else might I be overlooking?    Or just a corrupted file??

(in P6)

... and 'Memorize All' on an unlocked frame, and then 'Restore All' on a locked frame does not unlock the dial, but neither does the reverse process lock the dial when a locked frame is memorized and applied to a previously unlocked frame. 

However, saving the entire animation as a pose file WILL apply the lock-up to a previously unlocked figure.   But, then subsequently deleting all paramater settings in the range of this applied pose does not undo the lock-up created by applying the pose.

DOOH!  Feelin' like a nubie here!   What am I forgetting?

One thing you didn't mention, but probably did check anyway:  Is part of the timeline set to "Constant" interpolation for that one Actor?

This usually happens to me when I have more than one animation layer. Check the layers in the animation palette,

Well joy-joy!   Appears you were both right …I think.

Poked into the bowels of the file and found an unusual couple of lines of code in the .pz3 referring to “layer kfrm”, with the offending Hip:Y-Trans value set to Constant.  (was all set to Spline in the normal Keyframe window).

Now, I have absolutely no idea what an “animation layer” actually is – does that function even exist in P6?  --  I did do a quick RTFM, but didn’t see the term mentioned.  Will have to see if the good Dr. has a tute.

But, anyhoo, I whacked that part of code from the .pz3, & it’s working like a champ again. 

Thanks to you both for the cooperative head-scratching.  New turf for me & it was driving me crazy(er).

"A little of both", as the talking heads like to say.  That's rare in the technical world.... usually the problem turns out to be Neither One.

Those Animation Layers sort of halfway existed in P6 but weren't fully implemented or documented.   Looks like a programmer had started to develop the feature, and the testers didn't notice the incomplete action.   I don't think you'll get proper results by using them in P6.   They were fully developed in P7, but still don't behave the way I'd expect layers to behave.

Some people use them for building and modifying lip-sync on the face while leaving everything else alone.

Well that 'splains why I'd not run into it before... it was an old file I'd reopened, so not real sure what (pose file?) brought it into my scene.    Still somewhat astounded that I’d never seen, nor even heard “animation layers” mentioned here before.  

Was there ever actually any way to see, or modify, the Layered data in P6 - without resorting to hacking the text by hand?

... and I know you can't read all of'em, these days, so thanks again for checking-out my dilemma Ockham!

... and thanks again to CaptainMARC for snapping to the whole "layer" thing as the hidden source of my problem, -- and a belated welcome to the forum.  

(Sheesh... been hanging around here since day-one, and still have to get clued-in -- by a member that just joined!!   DOOH!   What a charmingly helpful neighborhood this still is!)