sometimes if you do http or skip www on a web site it will not resolve correctly if they do not have the server set up right. For example: try http://weatherunderground.com and try http://www.weatherunderground.com. One works and the other doesn't because their server is not set up correctly or completely.
Weird... It doesn’t work for me even if I put the full address in. If you do a Google search, it seems that there are a lot of people having problems, but there are many who are not. I don’t know what’s going on.