Go to sh404SEF Configuration
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Go to Administrator >> sh404SEF >> View/Edit SEF URLs
Search for the Problem URL
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Search for the URL that is causing you problems. When you've found it, click on the box next to the URL and then click "Duplicate URL" in the top-right corner.
Examine the URLs
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You will hopefully see more than one possibility for each URL. The key part of each URL is "Itemid=XXX". This controls which modules and templates appear on a page. The URL with Rank of 0 is the current URL. In order to get different modules and templates to appear on a page you need to choose a URL with a different Itemid. In this case we'll try the second URL which has Itemid=207
Choose a New URL Possibility
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Check the box next to the new URL possibility you want to try and click "Main URL" in the top-right corner. Check the front of your site to see if this has solved the problem. If not, repeeat the process and test another URL possibility.