This sounds like it may be a pathing issue to the image. The best way to determine if it is a path issue is to use the source button to view the source for the image. In the <img tag you will see the src attribute. This is the path that is being used for the image, you should be able to take a look at this path and try to match it up to the correct path to the image on your server. Let us know what you discover.
If you have any trouble with this we can take a look for you to see if we can spot the issue, let us know.