[nag] Cannot create Task

[TPSA]

I'm new in nag configuration.
I configure Horde-3.0.4 and Nag-2.0.1 create database and configure my 
backend as SQL.
Configuration is created to use custom setting because horde_defaults always 
return error during DB connection.
With custom setting I can open Task application but I cannot add new task 
because I receive following error

Jul 07 15:18:59 HORDE [emergency] [nag] DB Error: connect failed: 
[nativecode=Access denied for user: 'horde at localhost' (Using password: YES)] 
** Array [on line 448 of "/var/www/html/horde/nag/lib/Driver/sql.php"]

I suppose that password is not correct but I don't know why it not use 
custom setting password.
Can someone help me with it ?

Robert