I have been fighting the same problem with the same results. It turns out that startsearcher was loaded in with a template from facethemes.com. If you bring up Firefox:Tools:Add-ons you can see "Facethemes" listed as an extension, but the Uninstall button is greyed out. "Disabling" had no effect. Fortunately however, the operating system (Vista on my computer) can uninstall it. Go to the control panel:Programs and Features select Facethemes and uninstall it. Worked for me.

Good Luck.

Dude, thank you so much, I couldn't delete that ****'ing thing off my computer, and somehow it randomly appeared there in my FaceBook? Like, I said something was not right, I had ads popping all over my damn page, and I couldn't find out what the hell it was, and how to remove it, thanks again man you're the best!