aakk9999 - 8:57 pm on Jan 8, 2013 (gmt 0)

Quite dont understand what you mean with this: "I would therefore carefully inspect your URLs, perhaps using "site" command narrowed down by using "inurl" string using some filters, to see where these "Not selected" are coming from. I don't think they are because of 404 errors. " Do you mean searching in google?

What I meant is that you could do something like:

site:example.com inurl:*php*someparam=

which will (for example) return all URLs that are php pages and which Google has in its index that use this particular parameter in URL. Often you will get message "...we have omitted some entries very similar to the 3 already displayed..." in which case you should click on "repeat the search with the omitted results included" to get the number of URLs indexed but "Not selected".

Trying this with different URL patterns and different parameters can show you which URLs may have problem in (perhaps) duplicate content, thin content and similar and you can check whether you have addressed the problem with blocking these via robots or noindexing them or in some other way.