After several weeks of investigation, I've come to a conclusion that if a site has large number of internal broken links (originating from a domain and terminating on non-existent locations on itself), Google would push the domain down. There seems to be a mixed opinion / experience on this issue though. Some of the webmasters have experienced that if the site has internal broken links - then the site rankings go down (and come up as the count goes down). There are several others who say that such links won't hurt your rankings. What's your opinion / experience?