My computer won't let me open more than 1 Firefox browser at a time. If I close my 1 Firefox browser I can't reopen it unless I use Windows Task Manager to END the Firefox.exe process. It seemed to begin after I updated a different program, but not sure if that is the cause... still a problem even after uninstalling that program and re-installing Firefox twice. The customized Firefox on my Ironkey works fine and Internet Explorer works fine. Firefox had been working fine for more than a year.