Dynamical.Biz

Without any technical reason (as far as I know) webmastertools (Web
crawl errors > Not found) reports 10.3790 errors for my site http://lamundial.net

I've checked the server errors log but no clues, this non existing
urls have a strange pattern that makes me think in a glitch in
googlebot but everything toghether is quite odd.

PR has been dropped from 6 to 4. Could this be the reason?

Someone had a similar experience?
Thanks