Getting the following message from Package Manager in Ubuntu 11.10?
Requires installation of untrusted packages
The action would require the installation of packages from not authenticated sources.
And when you click on the Details dropdown it shows all of the packages that need to downloaded?
Run the following commands:
sudo mv lists lists.old
sudo mkdir -p lists/partial
sudo apt-get update
These commands will save a backup of the old lists and then create a new lists folder.
More information can be found here.