Is this an opendkim or a dns problem?

[Nagy László Zsolt]

Log:

Oct  2 07:01:04 shopzeus opendkim[2918]: 20412889B806:
mail-wi0-f181.google.com [209.85.212.181] not internal
Oct  2 07:01:04 shopzeus opendkim[2918]: 20412889B806: not authenticated
Oct  2 07:01:09 shopzeus opendkim[2918]: 20412889B806: key retrieval
failed (s=20120113, d=gmail.com): '20120113._domainkey.gmail.com' query
timed out
Oct  2 07:01:09 shopzeus postfix/smtpd[14570]: disconnect from
mail-wi0-f181.google.com[209.85.212.181]

However:

 # dig 20120113._domainkey.gmail.com txt

; <<>> DiG 9.10.2-P4 <<>> 20120113._domainkey.gmail.com txt
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 2733
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;20120113._domainkey.gmail.com. IN      TXT

;; ANSWER SECTION:
20120113._domainkey.gmail.com. 204 IN   TXT     "k=rsa;
p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA1Kd87/UeJjenpabgbFwh+eBCsSTrqmwIYYvywlbhbqoo2DymndFkbjOVIPIldNs/m40KF+yzMn1skyoxcTUGCQs8g3FgD2Ap3ZB5DekAo5wMmk4wimDO+U8QzI3SD0"
"7y2+07wlNWwIt8svnxgdxGkVbbhzY8i+RQ9DpSVpPbF7ykQxtKXkv/ahW3KjViiAH+ghvvIhkx4xYSIc9oSwVmAl5OctMEeWUwg8Istjqz8BZeTWbf41fbNhte7Y+YqZOwq1Sd0DbvYAD9NOZK9vlfuac0598HY+vtSBczUiKERHv1yRbcaQtZFh5wtiRrN04BLUTD21MycBX5jYchHjPY/wIDAQAB"

;; Query time: 0 msec
;; SERVER: 80.249.168.18#53(80.249.168.18)
;; WHEN: Fri Oct 02 07:05:36 EDT 2015
;; MSG SIZE  rcvd: 462

How can the key retrieval time out? Is it because opendkim uses a
different name server? (Why would it do that?) What is happening here?

Thanks,

   Laszlo