RHEL 6.2 boot stalls after rhsmcertd

My linux machine running Red Hat Enterprise 6.2 crashed all of a sudden and now it is not booting up.
It starts the booting process properly, but get stuck after the message "Starting rhsmcertd". What process comes the next where it is getting stuck?
Is it my X11?

I tried to use the single user mode and it boots without any problem. There is a lot of memory available, so that is not the issue.
From the single user mode, when I tried "telinit 5" it get stuck again at the same process.

Can anybody help me to boot up my machine properly?