Well, I followed the solution by vbspam and the one found here:  http://community.linuxmint.com/tutorial/view/848, but none of them worked for me. At least not as I thought it will work.

I was used to the way keyrings worked in gnome: the first time in a session I opened a password protected program like filezilla, seahorse asked for the password to unlock it. Mate keyring has never asked for a password, with or without autologin enabled.

All mate keyrings related are running, all gnome keyrigns disabled; seahorse show the passwords (login and default) but anybody can enter in filezilla and into the cpanel of my web sites which means a security risk for me.

 ps ax | grep keyring
 1550 ?        Sl     0:00 mate-keyring-daemon --start --components=gpg
 3273 pts/0    S+     0:00 grep --colour=auto keyring

 ls /home/salva/.config/mate/keyrings
 default        user.keystore
 login.keyring  predeterminado.keyring


~/.config/autostart $ dpkg -l | grep keyring
ii  add-apt-key                            1.0-0.5                                 Command line tool to add GPG keys to the APT keyring
ii  gir1.2-gnomekeyring-1.0                3.2.2-2                                 GNOME keyring services library - introspection data
ii  gnome-keyring                          3.2.2-2ubuntu4.1                        GNOME keyring services (daemon and tools)
ii  libgnome-keyring-common                3.2.2-2                                 GNOME keyring services library - data files
ii  libgnome-keyring0                      3.2.2-2                                 GNOME keyring services library
ii  libmatekeyring                         1.4.0-1+precise                         MATE keyring services library
ii  libmatekeyring-doc                     1.4.0-1+precise                         MATE keyring services library (documentation files)
ii  libpam-gnome-keyring                   3.2.2-2ubuntu4.1                        PAM module to unlock the GNOME keyring upon login
ii  linuxmint-keyring                      2009.04.29                              GnuPG key of the Linux Mint repository
ii  mate-keyring                           1.4.0-1+precise                         MATE keyring services
ii  mate-keyring-dbg                       1.4.0-1+precise                         MATE keyring services (debugging symbols)
ii  mate-keyring-doc                       1.4.0-1+precise                         MATE keyring services (documentation files)
ii  medibuntu-keyring                      2008.04.20                              GnuPG key of the Medibuntu repository
ii  python-gnomekeyring                    2.32.0+dfsg-1                           Python bindings for the GNOME keyring library
ii  python-keyring                         0.9.2-0ubuntu0.12.04.2                  store and access your passwords safely
ii  ubuntu-extras-keyring                  2010.09.27                              GnuPG keys of the Ubuntu extras archive
ii  ubuntu-keyring                         2011.11.21.1                            GnuPG keys of the Ubuntu archive

(None of the gnome keyrings have been changed to show in mate (as I have not using them))

The only extra thing I have done, is to modify 2 files in /etc/pam.d/ (mdm and mate-screensaver)

For
"@include common-auth"
I added
"auth    optional        pam_mate_keyring.so"

And for
"@include common-session"
I added
"session optional        pam_mate_keyring.so auto_start"

Not being an expert in the console and commands, I really have no clue if I'm doing something wrong or the truth is that mate keyring will never work as the gnome keyrings.