For those who have posted images to this and other forums only to see the BIG RED X instead of the picture, here is the explanation (but not the solution).
When you post a message that contains an image that resides on a server other than CruiseMates, your browser attempts to download that image from the source server through the Cruisemates server. Some servers, but not all, will prohibit downloads when the source is "referred" by another server. Therefore your browser can not make a connection to the server where the picture is located and it displays a BIG RED X, meaning that there is no picture information available.
If you right click the picture and copy and paste the URL into your browser's address line, you can download the picture because the URL is no longer "referred" by the Cruisemates server. Your browser then caches the picture (or at least the path to it) so it doesn't need to download it again through the Cruisemates server. If you then backspace to the article, your browser can then display the cached picture.
Unfortunately there is no way to tell which servers prohibit downloading when the URL is referred by another server. If you attempt to embed a picture and get the BIG RED X, note the site and don't try to use any more of their image files. You can always right click on the picture and save it to disk and then upload it to a Cruiesmates gallery. Then use the gallery as your source URL instead of the site that prohibits referred downloads. This should always work.