> If I open up the
> drop down selector above the sample image, the only choices I have are My own
> image file name, or From Gradient, or From Reverse Gradient.
ahh, possibly your sample image is a GIF?
Please check the Image->Mode menu and make shure it is set to RGB.
That's an ugly pitfall, because many operations only work on RGB images
and GIF images are loaded as "indexed color images" (=256 color only).
Same goes for grayscale images.
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