I have FF (ver 3.6.17) open and when I click on the "+" on the far right most tab to open a new tab (the tool tip even says "Open a new tab"), nothing happens. I click on File, New Tab and nothing happens. I opened up a new browser window, clicked on the tab next to the currently opened tab and nothing happens. I've clicked Tools, Clear Recent History, Everything. I've restarted the PC. Nothing seems to work. This only started being a problem a couple days ago. Any idea what could be wrong?