I did something stupid.
I duplicated a layer that was set up with key frames and operators for the front of an animation, and used the duplicated layer for for the end of the animation where I changed it.
I now, or course, have discovered that the front of the animation using the original layer has now changed to the settings I applied on the duplicated layer at the end of the animation.
Is there a way to select a duplicated layer, and change it so that it is independant of the the original?
That would save a lot of rebuilding.