Passwd getting locked

Hi, there is a password lock problem happening everyday at one of the servers(GNU RH-Linux;kernel release version 2.6.18-308.20.1.el5) for a particular user id which is an appln user id. Everyday it needs to be reset by the owner/unix user mgmt team. My suspicion was if any cronjob was running using old passwd then the user id/passwd would get locked after 3 unsuccessful attempts. But unable to find any. Don't know how to go further.
Request help and advice in this regard.

check the /var/log/secure file. You can find the user login details there

Hi Hari, first of all thank you. I tried checking the /var/log/secure file but it is having root privilages for read/write. I'm not a root user. I'm just an appln user. So how do i go further?

Not only could it be a cron job on this system, it could be a cron job on another system trying to login to this account.

Are you aware of any inbound account usage from other system? eg. regular ftp or something like that?