Safari keeps logging me out of places.

I have at least five websites marked "keeped me logged in", including Facebook, Apple, and even the region and language notice on YouTube keeps reappearing for me to accept it every single time, but every single time I close the window - I'm being logged out, and next time I open the site I need to log in again.

I already enabled cookies from all sites, and they seem fine, but this has been going on for months.

Using Lion 10.7.3.