I’m having problem using these constraints, it is popping in certain angles. Here is the file: http://www.pasteall.org/blend/22341
I tested with copy rotation, with and without parent, Transformation Constraint, World, Local, Local with Parent and Pose Spaces… All gives the same results, some in diferent angles!
Is it a bug, a limitation or just me doing something silly?
The two bones that are popping are children of the main control bone, the third bone that isn’t popping has no parent. Not sure what kind of motion you are after, but if the 2 popping bones don’t have a parent, they don’t pop. If the two popping bones are set to not inherit their parent’s rotation (bones panel, under the parent field, it’s a check box) the bones don’t pop.
I think you have a problem in that the bones are inheriting their rotation from their parent, and copying it via the constraint at the same time.
On any bones were you have a Transformation Constraint… if your only going to use a Rotation to Rotate a Rotation then, you might as well just use a Copy Rotation Constraint… the Transformation Constraint is better used for transfering location motions into Rotations or a Scale motion to a Rotation… or Rotation to a Location… etc…In times past… the Transformation Constraint has been very picky and buggy… Might work fine in Latest version however…