Looking at my logs I only see 5 requests (maybe I'm grepping for the wrong thing?) but the UI shows many more links checked.

  grep www.drlinkcheck.com  /var/log/nginx/access.log | wc -l
  5

All of those have the user agent 'Mozilla/5.0 (compatible; dlcbot/0.1; +http://www.drlinkcheck.com/)

Also, I think it would be useful to add a section in 'About' that says the user agent the crawler will use.