For the last few days phone software behaved incorrectly by shutting down without notification and battery meter did not showed as charged many-a-times.
I posted this on http://forums.se-nse.net and they helped me in reviving my phone. Below is the link to the post:
Typical solution is to flash your phone.
Another useful link is http://forums.se-nse.net/topic/23459-tutorial-general-usage-xs-v31/