I finally had to disable Ghostery...prevented me logging on here!
That shouldn't have prevented you logging in, being it is only for disabling tracking devices.
I have Ghostery, No Script and Ad Block running and I have no issues logging in... with WC and Stardock added to the whitelists.
Google Analytics is a tracking script. It wont harm your system but you will get targeted ads.
That's why I installed Ghostery and the ad blocking proggies. A while ago I mentioned something about a spider bite in a forum thread and the next thing I knew I was getting Aussie pest control ads when not logged in... which I always should have been as I have FF remember my login details. However, around that time, I was frequently being logged out for some reason and kept getting damned ads for crap I'd never buy.
Since enabling Ghostery, No Script and Ad Block, though, I've not had any issues, other than a few site related ones during and after the change over to the new format.