Imagecache troubleshooting

I am setting up image galleries using the node_gallery module.  However, no images were showing.  The ImageCache module was reporting the following:

Failed generating an image from 2_ugalaw591.jpg using imagecache preset node-gallery-display.

That tells me a lot.  I was actually kind of missing the Grails stack trace (Ha ha!).

Once I enabled the module "ImageAPI GD2", all was well!