Try cropping it and re-saving it as a different named image. I've had this happen, and it only resolved when I cropped the image (even just a sliver) and saved it as a new image. I have no idea why that sometimes happens.
"Our aim in Education is to give a Full Life." -- Mom to 4 AO Graduates, Grandma to 3
"Practically, nearly, almost and in all ways visible to normal mortals Invincible" (due to the diplomatic immunity of Admin.)
"Practically, nearly, almost and in all ways visible to normal mortals Invincible" (due to the diplomatic immunity of Admin.)