DBM versions and pam_userdb.so PAM module

[Tom]

        Hello all!!


        I have to authenticate using pam_userdb.so but it cant open (or find 
or recognize) the dbm file(s). (Debian woody, pam version 0.72).

        cat /etc/pam.d/pop ...
auth    sufficient      pam_userdb.so db=/etc/mailsystem/users debug

        grep /var/log/auth.log ...
...pam_userdb[665]: Verify user `tom' with password `xxxx'
...pam_userdb[665]: user_lookup: could not open database 
`/etc/mailsystem/users'
        
        I tried old version of dbm file format (.dir/.pag, version 1.x, made
with 'tie()') and also the new one (version 6, made with 'dbmopen()'). For
the new one, I tried to use filenames such 'users' and 'users.db'. All
times I get the error: user_lookup: could not open database 
`/etc/mailsystem/users'.
        
        Some hint?


        PS: I asked to debian-user list and other lists without returns =(
 Also, I know its also a DBM question, but here there are big chances
another one to know such problem, and the solution =)


        Thanx
        Tom