http://cookieswap.mozdev.org/notes.html#c63 Definitely different profile for each tab (ie. it remembers which profile is set)... or even better a new Create Tab with Profile "X" (or unique cookies) functionality. Mozilla/5.0 (Windows; U; Windows NT 5.1; en-GB; rv:1.8.1.8) Gecko/20071008 Firefox/2.0.0.8