Not able to create connections to http://dmoz.org/Health/Conditions_and_Diseases/Nutrition_and_Metabolism_Disorders/Vitamins_and_Minerals/Wilson's_Disease/ from your server.
The reason might be a firewall, proxy, or http://dmoz.org/Health/Conditions_and_Diseases/Nutrition_and_Metabolism_Disorders/Vitamins_and_Minerals/Wilson's_Disease/ or your web hosting company might be blocking outside connections.
Another possibility is a timeout because of slowdown in internet itself.