When searching in top category and product belongs to more than one category, in the result it shows up as many times as it how many it belongs to category. WHere and how the testing can be done to make sure that same product ID does not shows up more than once on search results page

The solution of the problem is a new canonical url link tag introduced by Google, Yahoo! and Live and tells the search engines which URL it should have for the current page.
Matt Cutts (software engineer at Google) explains the new canonical link tag:
 
The syntax is pretty simple: An ugly url such as http://www.example.com/page.html?sid=asdf314159265 can specify in the HEAD part of the document the following:
 
<link rel="canonical" href="http://example.com/page.html" />
 
That tells search engines that the preferred location of this url (the "canonical" location, in search engine speak) is http://example.com/page.html instead of http://www.example.com/page.html?sid=asdf314159265
 
What can it do for my webshop?
 
If search engines find the same content on irregular/different URL, the page/content will be marked as "duplicate content". This is a common mistake for a lot of websites which you really want to avoid since you want to have all your pages indexed properly. However, there are some factors that can lead to several URL's for one page.
 
Our coders wrote a canonical links plugin for ViArtShop. Its free.
You may contact us via Support Center http://www.viarts.ru/support.php?language_code=en
or support[at]viarts.ru
Best Regards,
ViArts Community

VST It sounds like a very good addition. Many thanks for your work.
 
As its free could you roll it back to ViArt for them to incorporate it in the main distribution?
besters
Ned