[Dovecot] dovecot2.0+ldap auth problems

I'm using a config from dovecot 1.2 adapted to 2.0

After update config, and restart dovecot service: If I do a doveadm user user1 then it is found correctly. If I do a doveadm auth user1 then it is ask for the password user, and it's running correctly.

But if I tray to login by telnet using IMAP then I get:

. login user1 pass1 Connection closed by foreign host.

I can see at logs a Info line with: Internal login failre with auth failed

It's very odd that with doveadm runs ok and but not with IMAP.