GAE website stopped working on custom domain

We have developed a website, which was wroking fine until some days back, but suddenly it stop开发者_JAVA技巧ped working on custom domain. It still wroks fine on appspot subdomain. I rechecked all the settings, they are all okay as per gae guidelines...

• http://www.thesudokutimes.com/ (This one is not working)
• http://thesudokutimes.appspot.com/ (It is accessible here)

Can any one suggest what could be the problem?

This does not seem related to Google App Engine but to a more generic DNS problem.
Using Dnsstuff tools you can see that your domain name was updated by your Registrar the 23th november 2010 and the IP for thesudokutimes.com can't be determined.

I suggest you to double check your configurations and contact your Registrar asking for support.