We see this question often, and 99.99% of the time
it is related to the site owner triggering our anti hack security
measures, and locking their IP address from our servers for 24 hours.

One of the way you could test to see if the problem is local or
server related, is to use a proxy. A nice proxy to verify if the site
is working is at http://ipinfo.info/netrenderer/ This free service
allows you to pull up your site in IE7, and other browsers to see what
it would look like. While this is designed to be used as a testing site
for IE rendering, it works great as a verification engine also.

If you site is coming up in that site, but still not at your
location, then you either have a local computer or ISP problem, or you
have been blocked.

If you open a support ticket, and supply us with your IP from http://www.whatismyip.com
we can check the server and see what is happening.