From 9.04 and onwards there has been a change in how the user is notified if there are available updates.
Read http://www.ubuntu.com/getubuntu/releasenotes/1004#Change%20in%20notifications%20of%20available%20updates
To restore how it used to be with the orange icon, run:
gconftool -s --type bool /apps/update-notifier/auto_launch false
From 9.04 and onwards there has been a change in how the user is notified if there are available updates.
Read http:// www.ubuntu. com/getubuntu/ releasenotes/ 1004#Change% 20in%20notifica tions%20of% 20available% 20updates
To restore how it used to be with the orange icon, run:
gconftool -s --type bool /apps/update- notifier/ auto_launch false