Backup problem - wrong username or password

==== Required information ====
- iRedMail version: 0.8.3
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): LDAP
- Linux/BSD distribution name and version: Debian 6
- Related log if you're reporting an issue:
====

Hello,
From couple of days I get this in my Logwatch mail:

[ERROR] MySQL username or password is incorrect in file /var/vmail/backup/backup_mysql.sh.
Please fix them first.

I check username and password and it's correct. I can without any problem login with username and password in that file to phpMyAdmin.

Any suggestions?

ag