Quote - No, that simply can't work. To flatten an unbent thigh, you need to move vertices in the z-direction. To flatten a thigh bent 90 degrees, you have to move vertices in the y-direction. But adding or subtracting another morph does not change the direction your vertices move in in your flattening morph.

So I was trying to do the impossible! It makes sense when I hear you explain it, but I could not get my head round what was happening at the time.

Quote - ... maybe you could convince Poser to apply the morph after the bend...

There is a thought. I suspect that placing the morph at the bottom of the channel stack might achieve that. I will test that idea. Easy enough to hack a cr2, but makes distribution a problem, unless you would be willing to put three or four blank morph channels at the bottom of hip2, and perhaps a couple in each thigh. But I suspect you may not want start making unnecessary modifications to the cr2 at this late stage.