I recently upgraded from 11.10 to 12.04. My first attempt failed, and I received an error stating that not all of the required packages were downloaded. Before (successfully) attempting again, I noticed that there was no longer a networking indicator in the upper panel. The indicator did not reappear with the installation of 12.04.

To be clear, my wireless connection has experienced no problems, despite the missing indicator.

Here are the solutions that I have found which did not work for me:

1. Editing /etc/NetworkManager/NetworkManager.conf and replacing [ifupdown] managed=false with =true.
2. Reinstalling network-manager (via apt-get install --reinstall).

I am currently running 12.04 on an Asus Eee PC 1005 HA, and I am new to seeking solutions through forums, so I apologize if I have neglected to provide some vital information about my hardware.