Hi Jam - One of my last discoveries when working with Fragmo was that you could eliminate some of the twist bone issues in IK by linking the arm bones as follows using animation links:
Link the the twist bone sharing the same location as the elbow bone (L Forearm>L Fore Twist) with the "Copy" setting.
Here's the Fragmo forum thread post:
And here's my dormant Cubby link of a Fragmo file example (FYI - LogMeIn is going to delete this soon but I figured I'd use it since it's still active)
(Edit: I highlighted the Right Forearm link in the screenshot but you get the idea. The Left Forearm is the control bone and the left forearm twist is the linked bone.)
Great, John! I remember I've took a look at this thread when beginning to work with Fragmo, but back then I couldn't imagine how inconvenient could be this arrangement of the twist bones. IIRC I didn't realize this feature (animation linking) is only available in the Schema view so failed to follow the instructions there and lost interest, but, as I've said before, then this was not a major issue to worry about.
When working with Forward Kinematics what I use to do is selecting both the main bone and the twist bone associated, and to apply the transformation to both; most, if not 100% of the time it works like a charm. But with IK, which is far more convenient for limb animation, I was plagued by this inconvenience.
Now, what's really annoying is that the problem derived from a rogue twist bone is not always apparent. I mean, I became aware of this problem when I have just finished to create every planned riding animation; so I created a new movie with the full sequence of animations. When the left shoulder of the puppet unexpectedly became so utterly distorted, I was first surprised and then aghast. So I have to re-check, correct and re-export (first to Milkshape, then to Cal3D) every riding animation. And I was surprised one more time when, once finished all that bothering work, I re-watched the demo clip I uploaded to Moviestorm and no such a defect was apparent!
So thanks a lot for such an useful contribution!