mysql shell client can't connect to maxscale

I just moved from haproxy to maxscale in front of a 3 node mariadb 10.0.17 galera cluster.
Now it seems the mysql shell client is broken, when connecting to maxscale:

mysql -utestuser -ppassword -h mysql.local.net mydatabase -e "show tables;"

ERROR 1045 (28000): Access denied for user 'root'@'192.168.111.31' (using password: YES) to database 'mydatabase'

when i connect to one of the mariadb servers directly it works:

mysql -utestuser -ppassword -h mysql1.local.net mydatabase -e "show tables;"

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Whats the problem here?

In skygw_msg1.log i also found some entries like:

"2015-03-16 15:09:01 Galera Service: login attempt for user testuser, user not found."