If you cannot get the banner shadow, is it because you don’t find it in the Layers palette? or because you cannot “grab” it to move it?
If you don’t have it in the Layers palette, maybe it is because you added the shadow on the same layer. In that case, there is no chance to move it.
If you have it in the Layers palette, but can’t seem able to grab it, activate the layer, then holding the Shift key, the Move tool will move it even if you cannot grab the correct pixel.