Savanadry - 1:38 pm on Jun 17, 2013 (gmt 0)
Are you using wordpress? If you are it would be very easy to add canonical links through a plug-in like yoast.
If you're not using wordpress then you need to add canonical links somewhere in the header of both pages. Both leading to the same correct page.
<link rel="canonical" href="http://www.example.com/WebmasterWorld/google-seo/no-specifics/>
For more info:-
BTW on a technical level if only one page actually exists it seems there are some probs with your htaccess file - but a quick fix would be to just add canonical.