<td><a href="http://www.maritime-sda-online.com/forums/ubbthreads.php?ubb=cfrm"><img SRC="/ubb/msdaol3.png"></td>
This line you created in your custom "HTML Includes" contains broken HTML, and is causing all of the following page items after it to become links.
You previously had added broken HTML, on your forum. The affect of your broken HTML would make everything that was clicked on, a link which would open in a new tab. After you fixed your broken HTML, your website's functionality was fixed.
Could it be that this is what your user is requesting?