How can I upgrade to Firefox 34.0.5 on Ubuntu 14.04?
Solution 1:
Apparently, Firefox 34.0.5 is the version that switched US users from Google to Yahoo search. (source here)
Firefox in Ubuntu and derivatives is unaffected, but if you wish to switch the default search engine to something else, just change it in the search bar.
PS: I can also confirm that Firefox 34 is not "upgradeable" to 34.0.5 on Windows, ...probably because I am not in the US.