Yes, you need to make the layers the way you want them before opening them in frames.
If you need to edit the frames, you delete all of them (except one - IN THE ANIMATION WINDOW, not Layers!) then change the layers.
Then you click the arrow at the top right of the animation panel (assuming you're in windows, I don't use a mac) and select 'Make frames from layers' to reimport the frames.
( ,
Sun 4 Oct 2009, 13:50,
archived)
Then you click the arrow at the top right of the animation panel (assuming you're in windows, I don't use a mac) and select 'Make frames from layers' to reimport the frames.