Synaptic claims I am using X.ORG X Server, Nouveau Display & states this device using an alternative driver. --304 is laisted, as are updates for it, as well as 173 (proprietry) which have worked ok in the past.
When I clicked on 304 & tries to use it, the system came up with error & wanted to report it.The instal (or similar) button disappeared.Bithing seemed t be happening, so closed it. On re-opening it states no proprietry drivers in use, so will try the re-start then update. 
Did that and got this:  Ign 
http://us.archive.ubuntu.com raring-updates/multiverse Translation-en_US   
Ign 
http://us.archive.ubuntu.com raring-updates/restricted Translation-en_US   
Ign 
http://us.archive.ubuntu.com raring-updates/universe Translation-en_US     
Ign 
http://us.archive.ubuntu.com raring-backports/main Translation-en_US       
Ign 
http://us.archive.ubuntu.com raring-backports/multiverse Translation-en_US 
Ign 
http://us.archive.ubuntu.com raring-backports/restricted Translation-en_US 
Ign 
http://us.archive.ubuntu.com raring-backports/universe Translation-en_US   
Fetched 25.7 MB in 40s (635 kB/s)                                              
Reading package lists... Done
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.
laurence@zorin:~$ 
It is still using that 'Nouveau' driver.--Not sure how good that is.--Google Earth still glitchy and then crashes.
I also notice that under Synaptic-Settings-updates, that the Updates page has everthing de-ticked. --Rgds.