Photoshop Gradient Map Adj Layer, Transparency Not Working

[keebler729]

When I select a preset using the gradient map adjustment layer (not the gradient adjustment layer and not the gradient tool) a horizontal bar (I'll call it #1) showing the preset appears. All the colors are fine but transparent regions are not shown in the bar or on in my image in the layers panel. When I use the gradient editor I can change the colors okay. And the colors changes are immediately shown in the horizontal display in the editor (bar #2) and on the gradient map (bar #1) and in the image. But any opacity changes I make (including making regions transparent) are only shown in bar #2 and are not shown in bar #1 nor the image. When I click ok in the gradient editor, the editor vanishes as it should and I'm left with bar #1 and the image without the desired opacity changes. There must be something simple I'm overlooking. Any suggestions? I have a Windows system that works well in other Photoshop operations.