Linux – LDAP+SAMBA login issues

I'm on a clean Ubuntu 13.10 install and I've just installed and configured openldap+samba. While I'm trying to configure a domain controller plus user shares. In order to ease LDAP management I've also installed gosa and lam ( LDAP Account Manager ).

My issue regards to samba when it's trying to connect to ldap:

# pdbedit -L -Uadmin
smbldap_search_domain_info: Searching for:[(&(objectClass=sambaDomain)(sambaDomainName=PBA))]
smbldap_open_connection: connection opened
failed to bind to server ldap://localhost with dn="cn=admin,dc=exedra,dc=cat" Error: Invalid credentials
        (unknown)
Connection to LDAP server failed for the 1 try!
smbldap_open_connection: connection opened
failed to bind to server ldap://localhost with dn="cn=admin,dc=exedra,dc=cat" Error: Invalid credentials
        (unknown)
Connection to LDAP server failed for the 2 try!
smbldap_open_connection: connection opened
failed to bind to server ldap://localhost with dn="cn=admin,dc=exedra,dc=cat" Error: Invalid credentials
        (unknown)
Connection to LDAP server failed for the 3 try!

Here's the server log:

Nov 21 10:40:58 srv1 slapd[30707]: conn=1088 op=2 SEARCH RESULT tag=101 err=0 nentries=0 text=
Nov 21 10:55:42 srv1 slapd[30707]: conn=1089 fd=29 ACCEPT from IP=127.0.0.1:56558 (IP=0.0.0.0:389)
Nov 21 10:55:42 srv1 slapd[30707]: conn=1089 op=0 BIND dn="cn=admin,dc=exedra,dc=cat" method=128
Nov 21 10:55:42 srv1 slapd[30707]: conn=1089 op=0 RESULT tag=97 err=49 text=
Nov 21 10:55:42 srv1 slapd[30707]: conn=1089 op=1 UNBIND
Nov 21 10:55:42 srv1 slapd[30707]: conn=1089 fd=29 closed
Nov 21 10:55:43 srv1 slapd[30707]: conn=1090 fd=29 ACCEPT from IP=127.0.0.1:56559 (IP=0.0.0.0:389)
Nov 21 10:55:43 srv1 slapd[30707]: conn=1090 op=0 BIND dn="cn=admin,dc=exedra,dc=cat" method=128
Nov 21 10:55:43 srv1 slapd[30707]: conn=1090 op=0 RESULT tag=97 err=49 text=
Nov 21 10:55:43 srv1 slapd[30707]: conn=1090 op=1 UNBIND
Nov 21 10:55:43 srv1 slapd[30707]: conn=1090 fd=29 closed
Nov 21 10:55:44 srv1 slapd[30707]: conn=1091 fd=29 ACCEPT from IP=127.0.0.1:56560 (IP=0.0.0.0:389)
Nov 21 10:55:44 srv1 slapd[30707]: conn=1091 op=0 BIND dn="cn=admin,dc=exedra,dc=cat" method=128
Nov 21 10:55:44 srv1 slapd[30707]: conn=1091 op=0 RESULT tag=97 err=49 text=
Nov 21 10:55:44 srv1 slapd[30707]: conn=1091 op=1 UNBIND
Nov 21 10:55:44 srv1 slapd[30707]: conn=1091 fd=29 closed

As you can see there's a wrong password somewhere. It looks like samba provides a password while authenticating against LDAP while maybe it shouldn't as I can run search through ldap without password:

 ldapsearch -x -LLL -b dc=exedra,dc=cat 'uid=admin' -W
Enter LDAP Password: 
dn: cn=System Administrator-admin,ou=People,dc=exedra,dc=cat
objectClass: top
objectClass: person
objectClass: gosaAccount
objectClass: organizationalPerson
objectClass: inetOrgPerson
objectClass: sambaSamAccount
objectClass: shadowAccount
objectClass: posixAccount
givenName: System
sn: Administrator
cn: System Administrator-admin
uid: admin
sambaDomainName: exedra.cat
sambaAcctFlags: [XU         ]
sambaPrimaryGroupSID: S-1-5-21-2410480708-3229887800-873095019-21003
sambaSID: S-1-5-21-2410480708-3229887800-873095019-41002
loginShell: /bin/bash
homeDirectory: /home/admin
uidNumber: 20001
gidNumber: 10001

But I don't understand why my password here is blank. Here you can see the same above result but without using -W option so no password is asked nor provided:

ldapsearch -x -LLL -b dc=exedra,dc=cat 'uid=admin'
dn: cn=System Administrator-admin,ou=People,dc=exedra,dc=cat
objectClass: top
objectClass: person
objectClass: gosaAccount
objectClass: organizationalPerson
objectClass: inetOrgPerson
objectClass: sambaSamAccount
objectClass: shadowAccount
objectClass: posixAccount
givenName: System
sn: Administrator
cn: System Administrator-admin
uid: admin
sambaDomainName: exedra.cat
sambaAcctFlags: [XU         ]
sambaPrimaryGroupSID: S-1-5-21-2410480708-3229887800-873095019-21003
sambaSID: S-1-5-21-2410480708-3229887800-873095019-41002
loginShell: /bin/bash
homeDirectory: /home/admin
uidNumber: 20001
gidNumber: 10001

If i provide a dn in ldapsearch sentence i'm force to authenticate:

# ldapsearch -x -h localhost -D "cn=admin,dc=exedra,dc=cat" -W
Enter LDAP Password: 
ldap_bind: Server is unwilling to perform (53)
        additional info: unauthenticated bind (DN with no password) disallowed

If I supply the password everything runs fine:
During LDAP installation, I set up a LDAP admin password for my admin user called admin which credentials I use to login into gosa and lam without problems.
It looks pretty strange as I need the admin password when using LDAP web management tools.

Extra info

As I'm new to LDAP and I've just took a read at the following doc and once I thought I successfully installed and configured LDAP. I read the following doc to configure samba server against LDAP.

Through web management tools I also managed to add some users and groups without issues but I'm suffering lot of issues when trying to browse through samba.

Does anyone know where I went wrong? Thanks in advanced!