I know what's the problem !
Your are adding dots at the end domain name in TXT entries. When I remove then all works fine !!!
Without dots:
dig @192.168.1.8 private._domainkey.nowosci.org TXT
; <<>> DiG 9.9.3-rpz2+rl.13208.13-P2-RedHat-9.9.3-4.P2.el6 <<>> @192.168.1.8 private._domainkey.nowosci.org TXT
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 42831
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 2800
;; QUESTION SECTION:
;private._domainkey.nowosci.org. IN TXT
;; ANSWER SECTION:
private._domainkey.nowosci.org. 86000 IN TXT "v=DKIM1; g=*; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC+gJh2UdMMHjlJRcssPMe0t4wemhLpewL1SMSJZwMZ/BxBYN+NF9djyaipbJP2fSC1X6az1P/UfUlGb+N/HxbELHC8deoZ2Z4ot1z1OMN6k9rD7QqD+zZVBYtErJC7oREoDrGVVDUpW7C4XbF7otO2BRej+vnK7Q/+eT/LDw4XVQIDAQAB"
;; Query time: 6 msec
;; SERVER: 192.168.1.8#53(192.168.1.8)
;; WHEN: ?ro wrz 25 14:45:57 CEST 2013
;; MSG SIZE rcvd: 311
With dots:
dig @192.168.1.9 private._domainkey.nowosci.org TXT
; <<>> DiG 9.9.3-rpz2+rl.13208.13-P2-RedHat-9.9.3-4.P2.el6 <<>> @192.168.1.9 private._domainkey.nowosci.org TXT
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 62128
;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1
;; WARNING: recursion requested but not available
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 2800
;; QUESTION SECTION:
;private._domainkey.nowosci.org. IN TXT
;; AUTHORITY SECTION:
nowosci.org. 1800 IN SOA ns1.nowosci.org. admin.adminonline.gr. 2013092526 3600 1800 604800 1800
;; Query time: 9 msec
;; SERVER: 192.168.1.9#53(192.168.1.9)
;; WHEN: ?ro wrz 25 14:51:15 CEST 2013
;; MSG SIZE rcvd: 119