PTR Configuration Question

[Yann Debonne]

Hi,

I just had my ISP (sbcglobal.net) delegate authority to me for reverse DNS 
entries for my DNS servers.  I kept getting errors when trying to do a 
reverse lookup for my IP address (67.122.54.85) and I noticed in my logs 
that the inquires have an extra number (80):

queries: info: client 194.235.129.69#3291: query: 
85.80.54.122.67.in-addr.arpa IN PTR

So, in my PTR record on my DNS server, I added the 2nd line:

85.54.122.67      IN      PTR     milk.purecreamery.com.
85.80.54.122.67   IN      PTR     milk.purecreamery.com.

And now all reverse lookups work correctly!  So, what is that "80" digit, 
and how did it enter the picture?!

Thanks,

Yann