Samsung galaxy s duos 2 rebooting

I have samsung galaxy s duos 2 gt-s7582. I rooted my phone successfully. And the phone was running good until after some 15 days, my phone rebooted automatically. It boots normally again and after some 2 minutes, the screen freezes and reboots again. I performed data wipe/reset from stock recovery but the problem is that though it shows data wipe complete, there is no data wipe at all when i restart the phone. And the phone continues in restarting continuously. Flashing stock firmware through ODIN also shows success and the phone reboots. But the old ROM is not replaced at all..Please HELP !!!