new strangeness

["The Almighty Pegasus Epsilon" <pegasus@pimpninjas.org>]

this one i fully expect a smack in the head and a quick correction, but here's the problem anyway.

data:
%in:127.0.0.1
Z16.172.in-addr.arpa:dns1.my.net:pegasus.pimpninjas.org:::in
Z16.172.in-addr.arpa:dns2.my.net:pegasus.pimpninjas.org:::in
.16.172.in-addr.arpa:172.16.0.4:dns1.my.net:::in
.16.172.in-addr.arpa:172.16.0.29:dns2.my.net:::in
.my.net:172.16.0.4:dns1.my.net:::in
.my.net:172.16.0.29:dns2.my.net:::in

$  dnsq SOA 4.0.16.172.in-addr.arpa 127.0.0.1
6 4.0.16.172.in-addr.arpa:
118 bytes, 1+0+1+0 records, response, authoritative, noerror
query: 6 4.0.16.172.in-addr.arpa
authority: 
16.172.in-addr.arpa 2560 SOA dns1.my.net pegasus.pimpninjas.org 1162864396 16384 2048 1048576 2560

 dnsq SOA 16.172.in-addr.arpa 
127.0.0.1
6 16.172.in-addr.arpa:
211 bytes, 1+1+2+4 records, response, authoritative, noerror
query: 6 16.172.in-addr.arpa
answer: 16.172.in-addr.arpa 2560 SOA dns1.my.net 
pegasus.pimpninjas.org 1162864396 16384 2048 1048576 2560
authority: 16.172.in-addr.arpa 259200 NS dns1.my.net
authority: 16.172.in-addr.arpa
 259200 NS dns2.my.net
additional: dns1.my.net 259200 A 172.16.0.4
additional: dns1.my.net
 259200 A 172.16.0.4
additional: dns2.my.net 259200 A 172.16.0.29
additional: dns2.my.net
 259200 A 172.16.0.29

so what i'm getting, is no additional section on the full IP, and doubled additional on the truncated IP. if we ask a.root-servers.net
 about one of google's IPs:

$ dnsq SOA 99.207.14.72.in-addr.arpa 198.41.0.4
6 99.207.14.72.in-addr.arpa:
194 bytes, 1+0+7+0 records, response, noerror
query: 6 99.207.14.72.in-addr.arpa
authority: 72.in-addr.arpa 86400 NS chia.arin.net
authority: 72.in-addr.arpa 86400 NS dill.arin.net
authority: 72.in-addr.arpa 86400 NS 
basil.arin.net
authority: 72.in-addr.arpa 86400 NS henna.arin.net
authority: 72.in-addr.arpa 86400 NS indigo.arin.net
authority: 72.in-addr.arpa
 86400 NS epazote.arin.net
authority: 72.in-addr.arpa 86400 NS figwort.arin.net

it delivers all the additional it has, exactly once.

so i assume i'm overlooking something simple, possibly something in the docs, but i've looked, and i have no idea. anyone know what i'm doing wrong?