My question is very similar to Ubuntu 13.10, kernel still 3.8.0-31-generic.

Recently was updating to Saucy and the ethernet cable got unplugged. So I decided to run Software Update again, to reinstall files. It returned that "everything is up to date". But according to these command-line searches, that is incorrect. How can I install Saucy now safely from the command line?

sudo apt-get install lubuntu-desktop
Reading package lists... Done
Building dependency tree       
Reading state information... Done
lubuntu-desktop is already the newest version.
The following package was automatically installed and is no longer required:
  linux-image-extra-3.8.0-19-generic
Use 'apt-get autoremove' to remove it.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

sudo apt-get dist-upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

sudo apt-get update
Get:1 http://extras.ubuntu.com raring Release.gpg [72 B]                       
Hit http://extras.ubuntu.com raring Release                                    
Get:2 http://az-1.hpcloud.mirror.websitedevops.com raring Release.gpg          
Hit http://extras.ubuntu.com raring/main Sources                               
Hit http://extras.ubuntu.com raring/main i386 Packages                         
Get:3 http://az-1.hpcloud.mirror.websitedevops.com raring-updates Release.gpg  
Get:4 http://az-1.hpcloud.mirror.websitedevops.com raring-backports Release.gpg
Get:5 http://az-1.hpcloud.mirror.websitedevops.com raring-security Release.gpg 
Get:6 http://az-1.hpcloud.mirror.websitedevops.com raring Release              
Ign http://extras.ubuntu.com raring/main Translation-en_US                     
Ign http://extras.ubuntu.com raring/main Translation-en                        
Hit http://ppa.launchpad.net raring Release.gpg                                
Ign http://az-1.hpcloud.mirror.websitedevops.com raring Release                
E: GPG error: http://az-1.hpcloud.mirror.websitedevops.com raring Release: The following signatures were invalid: NODATA 1 NODATA 2

lsb_release -rd
Description:    Ubuntu 13.04
Release:    13.04

uname -r
3.8.0-32-generic