Getting an error “The update Safari can’t be saved” when trying to update using OS X Software Update? Here’s a quick solution, simply delete the Safari folder in the /Library/Updates/ folder and try the update again.
I couldn’t login to facebook using Safari, constantly cycling back to the login page with no errors, but could log in fine using firefox!? Eventually found the culprit was Safari’s private browsing option. This was left on from an earlier session, turning it off let me login.