dns/nameservers problem

[sbz]

Hello

I have a problem with my main domain freeextra.com:

http://www.dnsreport.com/tools/dnsreport.ch?domain=freeextra.com

I cannot fix it to work.
What I am doing wrong?

Notice that my other domains with virtual nameservers are ok!
Look:
http://www.dnsreport.com/tools/dnsreport.ch?domain=sound.gr