A WebmasterWorld thread has discussion on this topic and offers tips on what to do, to help you with this problem. Some of the advice includes:
- Include the duplicate content in an external Js, assign it to variables, and do innerHTML to some divs.
- Use XmlHTTPRequest (GET) to retrieve the data in XML format and then put it into the page.
- Use an Ajax POST and retrieve the XML content with this.
- Use robots.txt to block specific files and/or page naming conventions.
Forum discussion at WebmasterWorld.