Temporarily Unlinking A Layer
If you have a layer linked to another layer in CS2, you’ll see a Link icon appear to the right of the layer’s name (it appears there now, because the old Link column that used to appear to the left of layers is gone). If you hold the Shift key and click directly on that Link icon, that layer will be temporarily unlinked (you’ll see a red X appear through that layer’s Link icon). To relink it, just Shift-click on that icon again.