upgrading oem 10.2.0.4 agent to 10.2.0.5 agent. - getting error: nmehl_readAgentKey: File access fai

While upgrading from oem 10.2.0.4 agent to 10.2.0.5 agent, I am getting these errors:

2012-02-06 13:27:27,360 Thread-1 WARN http: nmehl_readAgentKey: File access failure2012-02-06 13:27:27,360 Thread-1 ERROR ssl: Open wallet failed, ret = 287592012-02-06 13:27:27,360 Thread-1 ERROR ssl: nmehlenv_openWallet failed2012-02-06 13:27:27,360 Thread-1 ERROR ssl: Error initializing SSL2012-02-06 13:27:27,360 Thread-1 ERROR http: 6: Unable to initialize ssl connection with server, aborting connection attempt: ret -12012-02-06 13:27:27,360 Thread-1 ERROR main: nmectla_agentctl: Error connecting to https://cernd1.pdc:1830/emd/main. Returning status code 12012-02-06 13:27:28,780 Thread-1 WARN http: nmehl_readAgentKey: File access failure2012-02-06 13:27:28,780 Thread-1 ERROR ssl: Open wallet failed, ret = 287592012-02-06 13:27:28,780 Thread-1 ERROR ssl: nmehlenv_openWallet failed2012-02-06 13:27:28,780 Thread-1 ERROR ssl: Error initializing SSL2012-02-06 13:27:28,780 Thread-1 ERROR http: 6: Unable to initialize ssl connection with server, aborting connection attempt: ret -12012-02-06 13:27:28,780 Thread-1 ERROR main: nmectla_agentctl: Error connecting to