In /var/log/messages, I get these lines: PAM_pwdb ... get passwd; pwdb: structure is no longer valid when a failed login takes place on a FTP session. I don't see that line when a valid username/password is used with FTP. Which leads me to believe that the shadow/passwd file is all fine, is this is a config issue or a bug? In /etc/pam.d/ftp file, if I comment out this line: auth required /lib/security/pam_pwdb.so shadow nullok then I don't get the "stucture no longer valid" messages (but of course, PAM is now out of the picture). I'm running FC3, all latest versions using "yum update", and proftpd is my FTP server.