Hosts contains a local translation from an url (like to an ip-address (like It's the first place the browser looks if you type in the url. If it isn't found there, the browser goes on and asks the DNS-server that's configured or assigned to it at the moment (see ipconfig /all).

DNS is just a translation table, distributed all over the Internet. So I think nobody is responsible if any particular DNS-server (or, in your case, probably more of them) doesn't contain the right information temporarily or more permanently.

All you can do is ask the company that hosts the server to get it's DNS on order. Or find another one, if they can't fix it. It's their responsibility to have your sites available to all the world. Definitely not yours. Any lawyer will get all money back you payed them, and more, to cover the costs you make for the switch. Only if just one ISP can't find it (with perhaps a few percent of your customers) it's a problem of that ISP.

Some diagnostics:
- (compare info for your site with another one)
- maybe (although I found earlier versions to be difficult to use) a freeware program called cyberkit