Well that test with the browser was just to see if you can connect to kh.google.com with a browser. You can do that so that's good. But now what's wrong? You have cable or dsl. You said dsl is that right? In you dsl log in and look to see if it is somehow keeping a dsl hosts list. If you have such a function turn it off and cancel that hosts file. It's like Google Earth is not getting the proper ip address for kh.google.com. I used to use a little program called CIP that would take all your bookmarks and dns look them up and saved that info in a custom HOSTS file on windows, Ip addresses changed and sometimes you would need to update that file for it to connect. This is almost like the same problem you are having. Google earth is looking to the wrong ip address for kh.google.com. Some routers also store such a host file. or dns lookup table.

I'm wondering do you have in your connection part of your router the dns part filled out with a number provided by your ISP or set to auto? I can't find that program CIP on the web no more.