In my webmaster site I'm getting about 2 messages a month from google stating that they're finding (404) soft errors meaning in simple words that they are finding duplicate urls (vbet translatated urls) because of the fast and growing indexing. What should I do to stop these warnings? Basically in my webmaster tools I only have 2 real (404) not founds and 102 not founds because of my robots.txt.
-Cache set to 15 days
-guestcache off