[chanh]

The .hu TLD registry has special requirements for domains before nameservers can be changed.

Please set up the e-mail address postmaster@yourdomain.hu or remove all MX records from the domain www.yourdomain.hu as long as the nameservers are being changed.

First, You just had to create the postmaster@yourdomain.hu, then your registrar will let you change the nameservers otherwise they won't.