Please post about Dynamic Drive Scripts in the Dynamic Drive Scripts Help section here where I've moved this thread, and in the future:
Please include a link to the DD script(s) in question in your post. See this post
for more information.
Do you mean:
If not, which script? If so, are you getting this error on the DD demo page or just on your own installation? If it's just your installation, please post a link to the page on your site with the problematic code so we can check it out.
If it is only on your page, double check to make sure you have content for each menu link that has a # tag href and that each one (each pair) is unique.