If you manually remove cookies then exceptions aren't honored, so all cookies within the selection are removed.<br /> The only way to keep specific cookies via an allow exception is to let the other expire at the end of the session or possibly use Private Browsing mode for sites from which you do not want to keep cookies. There are probably also extension that allow for better cookie management, so you can do a search on the Add-ons site (Tools > Add-ons > Get Add-ons) ---- Future Firefox versions will support Private Browsing per tab, this is already available as an extension. *Private Tab: https://addons.mozilla.org/firefox/addon/private-tab/ The Firefox menu button gets a purple background or you get a purple PB mask on the menu bar or tab bar (Linux) when you are in a PB tab and all Private Browsing mode tabs get a dashed underlining unless you are in permanent PB mode.