Hi, I transfered a site to another hosting provider about 12 hours ago, I moved all files and changed the theme, so it looks different from the original site. Just after I updated domain nameserver information, when I visit the domain without "www", it displayed the website on the new host; then I visited it with "www", it displayed the old site(on the old host). Now, it always displays the old site, even when without "www"; but it do display the new site when I visit it using another country's IP. So what's up?
you need to wait 74 hours for dns to copy around the world, after that time it should be fine. there's another issue here as well - you shouldn't be able to type in www. and non-www. urls for your site or you might suffer a google pagerank split. google '301 redirect www'
f3ze is right about the using a 301 redirect for non-www url. You can also flush your dns, on your own computer, usually, once it is flush, it is force to download the new one, and if your isp as ipdated, you will see only new site.