You may get the a page that has the following on it:
If you are the owner of this website, please contact your hosting provider:
It is possible you have reached this page because:
The IP address has changed.
The IP address for this domain may have changed recently. Check your DNS settings to verify that the domain is set up correctly. It may take 8-24 hours for DNS changes to propagate. It may be possible to restore access to this site by following these instructions for clearing your dns cache.
There has been a server misconfiguration.
You must verify that your hosting provider has the correct IP address configured for your Apache settings and DNS records. A restart of Apache may be required for new settings to take affect.
The site may have moved to a different server.
The URL for this domain may have changed or the hosting provider may have moved the account to a different server.
The filename will be: /cgi-sys/defaultwebpage.cgi
If you arrive on a page and it has the above content then this means there is either a configuration issue or an IP issue. You should contact your web host for an explanation of why you arrived at such a page instead of your site.