FaceTime HD stays on signing in screen

My facetime hd stays on a signing in screen stays for a while and later on it says

"Could not sign in. Please check your network connection and try again."

Four consideration:

1. I am using a valid Apple ID which I am using to sibmit this to the forum

2. I am using my network connection to submit this to the forum

3. Same thing happens with iMessage Beta

4. Mail, Safari etc. all my other apps that use Internet connection work.

Any comments will be appreciated.

Thanks