50-200 OIS problem
when I first got my 18-200mm lens and trying to zoom in on the moon, I was upset that OIS wasnt kiking it. Then I discovered any exposure with a shutter speed greater than 1 sec disables the OIS. Still have the OIS icon on the right side of the screen though, but I have to manually stabilize the camera.
However in your case, if the OIS works with one lens and not another, then my beginner skills will not be enough I'm afraid.