Your session lasted for less than 10 seconds

After doing lots of google and various trials , I was finally able to get the reason for the above problem.

Note: The same error can occur for various reasons, so my work around might or might not work for you.

The problem was with the permissions for the /tmp folder.

The permissions for the /tmp folder should be
rwxrwxrwxt
some one had changed this to
rwx------- 
So other than root no other user was able to start the Xserver session.
once I changed the permissions using :

sudo chmod a+rwxt /tmp

every thing is working fine.