If you have [http://kb.mozillazine.org/Browser.cache.disk.enable Browser.cache.disk.enable] set to true in about:config then you must modify [http://kb.mozillazine.org/Browser.cache.disk.capacity Browser.cache.disk.capacity] to '''0''' (Do not cache files on the hard drive). Or Browser.cache.disk.enable set it to false(Don't store cache on the hard drive). [http://kb.mozillazine.org/About:config About:config ] thank you Please mark "Solved" the answer that really solve the problem, to help others with a similar problem.

You will have to disable automatic cache management. *https://support.mozilla.org/kb/Options+window+-+Advanced+panel#w_network-tab See also: *Expire history by days: https://addons.mozilla.org/en-US/firefox/addon/expire-history-by-days/