My options are set to delete all cookies and other history automatically when I exit firefox however when I checked cookies today after I opened a new window all the sites cookies I had visited were still stored. I did not have another firefox window opened and I currently run NoScript, Ghostery and BetterPrivacy which have never stopped the auto delete from working before. I updated to firefox 4 awile ago and it didnt cause an issue either. So if you have any idea why it is not working please let me know.