levo - 11:58 am on Dec 7, 2012 (gmt 0)

Switch to 410. Also make sure that the server doesn't redirect

example.com/index.php/content to www.example.com/index.php/content
example.com/index.php/content?somequerystringthatyouredirect to example.com/index.php/content

If you have pages that redirect and end up with 404/410, Google keeps crawling them (at least it crawls them more often)