[squid-users] What is excess data?

I am getting:

2005/09/12 19:17:59| httpReadReply: Excess data from "GET
http://www.familink.net/pbserver/pbserver.dll?OSArch=0&OSType=2&LCID=1033&OSVer=5.1.2600&CMVer=7.02.2600.2180&PBVer=14&PB=familink"

in my cache log and I know it is my customers dialers checking for a new
phonebook list but why am I getting the error for Excess data?

Ryan Lamberton
FamiLink Company
Clean Internet Access
Received on Mon Sep 12 2005 - 20:42:14 MDT