g1smd - 10:05 pm on May 9, 2006 (gmt 0)

To whoever asked earlier: yes, the internal linking of your site has a big effect on how you are indexed. Run Xenu LinkSleuth and see what it says.

There are many types of duplicate content: www vs. non-www (use 301 redirect), multiple domains (use 301 redirect), same title and/or meta description (make them all different), same on-page content for multiple URLs, (e.g. parameters in a different order, or extra parameters, just don't, right!), and so on. The last is more work to fix, and needs certain versions of the page to be excluded using the robots meta tag, or maybe using the robots.txt file.