Postfix + SASL + MySQL = PROBLEM

[k K]

Hello.
I need help.

I want to use mysql database to manage smtp authentication.
I'm installing cyrus-sasl-2.1.21 with mysql support (from source 
code).
Here is my smtpd.conf

pwcheck_method: auxprop
auxprop_plugin: sql
sql_engine: mysql
sql_hostnames: localhost
sql_user: mailuser
sql_password: 123456
sql_database: maildb
sql_select: SELECT passwd FROM users WHERE userid='%u'
sql_verbose: yes

I'm running postfix.
And when I'm sending mail, in /var/log/maillog I can see:

postfix/smtpd[14871]: warning: SASL authentication failure: no secret 
in database
postfix/smtpd[14871]: warning: unknown[192.168.0.51]: SASL CRAM-MD5 
authentication failed
postfix/smtpd[14871]: warning: SASL authentication failure: Password 
verification failed
postfix/smtpd[14871]: warning: unknown[192.168.0.51]: SASL PLAIN 
authentication failed
postfix/smtpd[14871]: warning: unknown[192.168.0.51]: SASL LOGIN 
authentication failed

What's wrong?