Image no display: Mysteries of the unseen.

Good morning all,

This is my 1st post, i'm a new user. If I've posted to the wrong place or misstep, please let me know.

I'm having an issue with an image (.png) I've inserted into excel (please see the attached).

The image displays and prints the default no display picture. When i select the image with a left click and begin to rotate it, an ethereal manifestation of what the image should be is displayed.
The same effect is seen when selecting the image with a left click and holding the right mouse button to drag the image.

Its as though excel remembers what the image should be but won't display it. What's wrong with the image? how do i get it to display properly?

Thanks,

Flapjack