What do you have in your network settings for your DNS server? Is it the address of your router?
What that error message sounds like is it can't resolve the name. That name is valid. Are you using something like 'OpenDNS'?
Well, it needs to be either your router's IP address (something like 192.168.1.1, should be the same as your gateway and if you don't know that, there's instructions in the User Guide on how to determine what it should be) or a DNS service like OpenDNS (68.225.105.209). Make sure you reboot the Apex after making any network change.