There are a few options that you can try. My copy of simpleviewer.fla did not have the link enabled in simpleviewer-prosimpleviewer_prosource folder. Check to make sure you have the following found in the actions layer's action frame.
var IS_PRO:Boolean = true;
mcPreloader.mcLoader.mcTitle._visible = !IS_PRO;
If for some random reason this is not working you could always delete the link off the stage. Just make sure to back up your zip file in case something goes wrong.
There should be a file in the web folder ready to go without the link see below.
web folder contains files to post to your website. This folder contains a version of the SimpleViewer swf without the download link. To use this with your existing galleries, copy the viewer.swf from this folder into your existing gallery folders.
http://www.airtightinteractive.com/simp … ml#folders
SimpleViewer Support Team.