Eseries / Communicators :: E72 Always Showing Lock Code Error After FW Reinstalled

I am using my nokia E72 for the last 18 months. 3 days before I reinstalled phone's FW 081.003. From that day onwards my phone is asking me lock code. And always showing lock code error. I already used the lock code option for restarting phone. I changed the default 12345 to 543215 and the feature is working smoothly until 3 days before. Now what happened is that phone is not allowing any of the codes. I try 543215, 12345, 0000 everything I knew. But in vein. I cannot use my phone anymore.