I changed the Full Screen Edit to use the Thumbs and not the Selected Image.
Thanks for being a good sport this morning.
On a serious note, the default setting in the Page editor is small thumbs. As I said, it is for speed. If you need to see the high Resolution image, just click the HQ button.
As long as your thumbs are now of proper quality, you probably wont need Selected Image in the page editor.
Fred