fwiw Since this isn't a browser specific forum, why are you trying to save videos with firefox (when browsers are not really meant to do that) and not using something like vlc? Last time I checked (did this) there were tons of forum posts and the like on doing this with vlc. I've used vlc to save everything from YouTube to cspan (flash to real media) and then convert it. The one thing I haven't had to deal with using this method are logins, sessions, and post data (though, I'm sure if you look, vlc will handle that too somehow).