How to fix “Superfluous name server listed at parent” on “producaoaudio.com”

This means that your nameservers (NS records) are not in the zone configured on your DNS server.

You should be able to do:

$ dig yourdomain.se NS @yourdnsmaster

and get NS records as a result.

What they mean is that you are missing the so named glue records.

A glue record is the ip address of a name server held at the domain name registry. These are used to avoid some circular dependencies in name resolving.

Here's an example, from the wikipedia page:

Name servers in delegations are identified by name, rather than by IP address. This means that a resolving name server must issue another DNS request to find out the IP address of the server to which it has been referred. If the name given in the delegation is a subdomain of the domain for which the delegation is being provided, there is a circular dependency. In this case the nameserver providing the delegation must also provide one or more IP addresses for the authoritative nameserver mentioned in the delegation. This information is called glue. The delegating name server provides this glue in the form of records in the additional section of the DNS response, and provides the delegation in the answer section of the response.

For example, if the authoritative name server for example.org is ns1.example.org, a computer trying to resolve www.example.org first resolves ns1.example.org. Since ns1 is contained in example.org, this requires resolving example.org first, which presents a circular dependency. To break the dependency, the nameserver for the org top level domain includes glue along with the delegation for example.org. The glue records are address records that provide IP addresses for ns1.example.org. The resolver uses one or more of these IP addresses to query one of domain's authoritative servers, which allows it to complete the DNS query.

Hope this helps!