Firefox Browser, Irritating?

Even I am same kind of you. I have installed 3 to 4 browsers on my computer system. I am having opera, chrome, firefox, internet explorer, etc. But from all of them I am mostly using Google Chrome. I found it bit faster in compare to all other browsers.

About your problem, honestly I really don't know the answer. I can't predict the problem behind it. May be your system is facing some kind of virus which is opening your firefox browser automatically. Is your firefox is opening with some kind of page or blank page?