CMS New article image showing as a pencil
 

I've just promoted a post to an article, and now the thumbnail image on the cms page s showing the pencil image? which when i view its properties show as being in /images/misc/pencil.png, but when you click on the image the original pictures shows up, its the first time its done this.. Ive deleted the original image and uploaded another from my laptop and saved it and now its showing as the pencil again instead of the imae it should display??

Any ideas how to fix this??