KUser corrupts password file ?

[Sergiu Baluta]

I am running Freebsd  5.2.1 . I logged in as root into KDE and used KUser to
reset password for a user.
After that when I tryed to login as root and  I would get an error:

pam_acct_mng - ....  Account expired.

I booted in single user mode and tryed to change root password:

#mount -u /
#mount -a
#passwd root
..... (entered the new password)  ....

And I would get:

pwd_mkdb: 0 > max uid value (4294967295)
pwd_mkdb: at line #2
pwd_mkdb: /etc/pw.7BUxbZ Inappropriate file type or format
passwd: pam_chauthtok(): error in service module

What does this error mean ?

Is it possible that KUser corrupted my passwd file, and if yes is there any
way to restore it (at least the system users).

Is there any way and place to get and install the default password files 
with system accounts
and then I can add my user's accounts manually (I have only few) ?

Is there any other solution to this problem , or any hints how to debug ?

Thanks a lot