I tested plugin only a few times on my website ( and default whois servers) it gives a false \" not free\" when searching .dk TLD domains. Tested many digits and jargons. \" generic\" TLDs and many other country-codes seems to work.
Maybee the .DK registry has changed something. I will have a look into the DK whois service.
It seem\'s that the .DK Whois Service responds correctly at this time. Actually theres no chance to query .dk domains correctly.