CS3 Smart Sharpen will not show a preview in Preview window

After using ACR to tweak my RAW image, I moved it in to Photoshop for retouching. To end up I was going to apply Smart Sharpen. No image, only gray, appears in the preview window in Smart Sharpen. This is a .jpg file I am dealing with.

Thanks,

Buck

You need to have the background layer selected in order for a preview to appear in SS.

Rick