@Monkwarrior,

Yes, in Milkshape, Gmax, and Max you would never see anything strange.
To those animation engines the bone_weapons are simply children of
bone_Rhand and bone_shield, bone_shield01 are children of bone_Lhand
and everything works as you would expect. When we tried animating
bone_weapon by exporting it as an extra bone to a family of cas files, it worked
fine in Milkshape. We made it rotate around for the walk animation and
the spear (we did this on armored_sergeants) rotated just fine. The thought
was we would replace the spear with a bit of mesh for the sling and then
the sling would rotate but the hand would not, since the hand vertices
would be assigned to bone_Rhand. But when we put those animations
in the game we got the effect of the spears just floating away from the
models once they started walking.

This is why I believe there's something left over in the game engine that
recognizes the strings "bone_weapon", "bone_weapon01", etc. and interferes
with them operating in a normal fashion. Caliban's admonition to us was sort
of third hand, he said he remembered their animators seeing strange effects
when animating those bones so they dropped it.

Since many models do have weapons assigned to weapon bones and seem
to work alright I don't think you need to redo them, just remember when
you see funny things like the present problem you had that a possible
solution is reassigning to a regular bone.

Slings are sort of second on the list after fixing the seam problem for the
ms3dImportExporter script. Extra bones are one of those ticklish things where
you have to have a whole weekend to devote to the debugging because
you have to mod descr_skeleton.txt, the modeldb, and the EDU all at the
same time to get it to work.