Password wiped out for userid that starts App Server

I recently changed my App Server configuration so that it will be started by a userid that I created for that purpose.  After I made this change, I restarted the environment, including the App Server, and everything worked.  I tried to restart the environment two days ago to resolve a problem, and the Application Server would not start.  When I checked, the account that I created to start it (APPSTART) had a blank password.  I changed the App Server configuration to be started by the PS account and brought the environment up.  Today, I checked the password for the APPSERVER