Re: Firefox 3.6.3 has grayed out "clear cookies when firefox closes." Howdo I get this back?
Uncheck "Permanent private browsing mode", and the other options will become ungray.
The reason it's grayed out is that you have it set to always start in private browsing mode. This means that cookies are always cleared, so the option below doesn't apply. Hence, to avoid confusion, Firefox grays it out.