minimum number of days between password change

[Lukas Baxa <baxic-cs@seznam.cz>]

Hi,

I created an account guest to test password aging.
The aging info of this account is following:

> chage -l guest
Last password change                                    : Mar 16, 2010
Password expires                                        : Jun 14, 2010
Password inactive                                       : never
Account expires                                         : never
Minimum number of days between password change          : 76
Maximum number of days between password change          : 90
Number of days of warning before password expires       : 14

However, I'm able to change my password when logged in as guest
as many times I want the same day, even if minimum number of days 
between password change is set to a non-zero value.

Does anybody know where the problem can be? I'm using debian lenny
(installed two month ago or so) and I'm using PAM. The file
/etc/pam.d/passwd looks as follows:

> cd /etc/pam.d
> cat passwd

@include common-password

> cat common-password

password required         pam_cracklib.so retry=3 difok=3 minlen=12 
lcredit=0 ocredit=2 minclass=3
password required         pam_unix.so use_authtok md5 remember=6

The pam_cracklib module works fine and I suposse that password aging 
info should be checked by pam_unix. However, it doesn't work when
using passwd from the command line.

On the other hand, the maximum number of days between password change
works fine and if the user guest logs in after the timeout expires,
guest is forced to change his password before login.

Can anybody give me a clue?

Thanks,

Lukas