cdromupgrade connects to internet despite selecting "no" at the prompt

cdromupgrade asks if you want to connect to the internet to get updated package lists. The prompt specifically states that if you answer "no" then the network won't be used at all. I answered "no" and the updater tried to download new package lists. If I'm not connected to the network, then that is a fatal error in the upgrade.

I'm attempting to upgrade by mounting the alternate CD, and running ./cdromupgrade

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: update-manager 1:0.134.12.1
ProcVersionSignature: Ubuntu 2.6.32-41.88-generic 2.6.32.59+drm33.24
Uname: Linux 2.6.32-41-generic x86_64
NonfreeKernelModules: wl
Architecture: amd64
Date: Thu Apr 26 23:05:18 2012
EcryptfsInUse: Yes
GConfNonDefault:
 /apps/update-manager/check_new_release_ignore=
 /apps/update-manager/first_run=false
 /apps/update-manager/show_versions=false
 /apps/update-manager/window_size=(600,600)
InstallationMedia: Ubuntu 10.04.3 LTS "Lucid Lynx" - Release amd64 (20110720.1)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en_CA:en
 PATH=(custom, user)
 LANG=en_CA.UTF-8
 SHELL=/bin/bash
SourcePackage: update-manager
VarLogDistupgradeTermlog: