Newbie to Poser5, but not to character animation in general...

Can someone explain to me why, when cutting and pasting keyframes in the Animation Editor, "Twist" is not included? I'm loving animating (so far) in this thing, but I'm baffled by this one fact. If I've got any twist rotation applied anywhere to my character, I obviously don't get what I want. Toggling down the dials reveals that every other attribute gets copied if I copy the entire character, but "Twist" remains blank (unkeyed).

I figure there must be some logic to this, but what it is escapes me.

Thanks,
zane