Log in to Facebook to personalize your experience with this social plugin

I was unable to click on any FaceBook [Like] button until I enabled 3rd party cookies in FireFox.

With 3rd party cookie disabled, a FaceBook login pop-up window appeared each time asking to "Log in to Facebook to personalize your experience with this social plugin". Entering login/password wouldn't help. The pop-up appeared again and again.

(Tested on iframe version of FaceBook plugin, but I think that JavaScript version needs cookie, too...)