pg 8.3.0 unexpected sending network packet?

My local firewall came up with a warning about postgres wanting to send
a network packet and I'm wondering if anyone can shed some light on its
trying to do?

The only line in pg_hba.conf that's not commented is
host    all         all         127.0.0.1/32          trust

According to netstat -a, its only listening on 127.0.0.1:5432

The sender details matches to my computer.
129.180.49.84 is just another machine on the local network (not dhcp
server/dns server/wins server/default gateway)

--------- firewall message --------------
Parent Process :    C:\Program Files\PostgreSQL\8.3\bin\postgres.exe
Parent Version :    8.3.0.831
Parent Description :    PostgreSQL Server
Parent Process ID :    0xB8 (Heximal) 184 (Decimal)


File Version :        8.3.0.831
File Description :    PostgreSQL Server (postgres.exe)
File Path :        C:\Program Files\PostgreSQL\8.3\bin\postgres.exe
Process ID :        0xBA4 (Heximal) 2980 (Decimal)

Connection origin :    local initiated
Protocol :        Raw Ethernet
Local Address :     0.0.0.0
Local Port :        0
Remote Name :
Remote Address :    0.0.0.0
Remote Port :         0

Ethernet packet details:
Ethernet II (Packet Length: 56)
    Destination:     ff-ff-ff-ff-ff-ff
    Source:     00-12-3f-e9-e8-49
Type: ARP (0x0806)
Address Resolution Protocol (ARP)
    Hardware type: Ethernet (0x0001)
    Protocol type: IP (0x0800)
    Hardware size: 6
    Protocol size: 4
    Opcode: Request
    Sender hardware address: 00-12-3f-e9-e8-49
    Sender IP address: 129.180.49.116
    Target hardware address: 00-00-00-00-00-00
    Target IP address: 129.180.49.84

Binary dump of the packet:
0000:  FF FF FF FF FF FF 00 12 : 3F E9 E8 49 08 06 00 01 | ........?..I....
0010:  08 00 06 04 00 01 00 12 : 3F E9 E8 49 81 B4 31 74 | ........?..I..1t
0020:  00 00 00 00 00 00 81 B4 : 31 54 30 4C 02 01 00 04 | ........1T0L....
0030:  06 70 75 62 6C 69 63 A0 :                         | .public.

--
Klint Gore
Database Manager
Sheep CRC
A.G.B.U.
University of New England
Armidale NSW 2350

Ph: 02 6773 3789
Fax: 02 6773 3266
EMail: kgore4@une.edu.au