Left clicking on some links doesn't load, but opening in new tab always works.
The best way to share this problem was with a video. So here's a short 7 second gif demonstrating the problem.
http://i.imgur.com/k5Rs2WJ.gif
Basically on some links, generally on a google search but occasionally elsewhere, if I left click to open them it will not load, it shows it's loading, but doesn't. If I middle click to open new tab, loads just fine 10/10 times. I've tested the same links on both IE and Chrome, and they work fine, so it does appear to be isolated to Firefox.
Alla svar (2)
I think I might have figured it out. It occured to me while I only have a couple of addons (adblock, cookieExFilter and Remove Google Tracking) that remove Google tracking .. might interfere with clicking on a link. And apparently it does. Though I'd have to continue to use without the addon for a while to be sure of it.
There are many other extensions (and Greasemonkey userscripts) you could try to remove the tracking redirect from links. It may be that the one you have has not kept up with changes made by Google in those links.