I am having the problem on one of my three computers (and not the others) that Firefox (version 27.0.1) frequently freezes for several minutes at a time before becoming responsive again. It is making it unusable.
If, when this happens, I manage to open a terminal (not easy as the whole system has glued up) and type the command "top" to see which processes are running, in addition to the process "firefox" I see another process called "Browser" with very high memory usage. If I kill that one, Firefox remains open and becomes responsive again.
Any ideas about how to solve this?