Dude my website was working fine till yesterday,How have you configured the domain to point to our servers in your controlpanel at co.cc?
Also do you have an .htaccess file? If you do what is the content of it, that error is common when there's a misconfiguration of the .htaccess file.
It does opened for me, not problem at all.
It may, in any case, be a problem related to the network on where you are, or maybe your ISP is having issues with the traffic.