[Ubuntu-PT 7649] Ajuda: Erro em Script

[Fabiano Garcia Fonseca]

Prezados!

Estou tentando rodar o script que segue abaixo, mas ele sempre acusa que 
não consegue atualizar os pacotes.
Alguém poderia analisar para verificar onde está o erro?

#!/bin/bash

# This is a Vinux EasyInstall script it automates the installation of a 
suite of applications from a desktop
# icon, which will disappear if the packages are successfully installed. 
The menu launchers are not removed
# so you can install the packages again if you want to update them 
and/or reinstall them etc.

# Step 1: Ask for confirmation - if cancelled go to Step 8

if zenity --question --text "Do you want to install the Vinux Google 
Suite?"; then

# Step 2: Get user name and ask for admin password

b=$USER
gksu su

# Step 3: Update package list and check it was successful - if not go to 
Step 7

set -o pipefail ; if gksu apt-get update | zenity --progress --pulsate 
--auto-close --auto-kill --text="Updating package lists, please wait..." 
; then

# Step 4: Update packages and check that it was successful - if not go 
to Step 6

set -o pipefail ; if gksu apt-get -y install prism-google-groups 
googleearth prism-google-mail chromium-browser prism-google-calendar 
prism-google-docs | zenity --progress --pulsate --auto-close --auto-kill 
--text="Downloading and installing packages, please wait..." ; then

# Step 5: Delete desktop icon if it still exists and display the success 
message

a="/home/"
c="/Desktop/EasyInstall-Google.desktop"
if [ -e $a$b$c ]; then
rm $a$b$c
fi
zenity --info --text "Installation was successful - Press enter to finish!"

# Step 6: Execute if installation of packages fails - from Step 4

else
zenity --info --text "Installation of packages failed - Press enter to 
close!"
fi

# Step 7: Execute if update of package list fails - from Step 3

else
zenity --info --text "Update of package list failed - Press enter to close!"
fi

# Step 8: Execute if installation is cancelled - from Step 1

else
zenity --info --text "Installation was cancelled - Press enter to close!"
fi

# Step 9: Exit

exit=0