3ds Max :: Affect Pivot Change Doesn’t Stay

I’m using 3dMax 201 64 bit.I made kind of a robotic arm and I linked parts together. Then I changed the Pivot on each pieces of the arms.My problem is that sometimes the change I have made on with “Affect Pivot Only” doesn’t apply.I can see the gizmo of the Affect Pivot but the one that works is the original one. I don’t know why it keeps the old pivot active when I changed it. Sometimes, I click on “Affect pivot only” button and the good pivot comes back active. But doesn’t work every time.

How do I make the good pivot active?