registering domain names
 

Any idea why one registrar would say a domain is taken yet others say it's available?

found a few good domains that are available yet say taken, i think they are possible the some 8 million+ domains NSI has hoarded since years ago

Some make use of unreliable whois databases.

oh but the answer to your question is the following (sorry i misread at first)

Registrars usually resellers may be using their registrars whois which is not the global whois registrar which is i believe whois.nsiregistry.com althogh this may have changed, havnt used it in long time, seems to change yearly hehe

I just checked the registrar that said it was taken, and now it says available. Odd.