Anyone experiencing this? Is it just me or is it happening across the board?
Win XP, Mozilla Firefox 3.5.10
I pop into the website, I'm usually automatically logged in and find out I'm not. I log in, check some stuff, leave for a while and when I come back I have to log in again. I haven't clicked on anything or changed any settings to my profile telling the website to log me out.
Any clues?

we don't like you no more... :-p
(not me, no ideas, sorry)

Check if your mozilla is set to delete the cookies when its turned off.

Nope, never happened to me. (Vista, the latest Firefox)

Just an FYI but there is a random issue with Firefox in which it logs out certain users from all sites on exiting the browser. It happened to me when I was using Vista, I switched to Chrome then when I installed Win 7 it stopped doing it for a while but was gawd awful with flash games (which I play occasionally).
The easiest thing to do is to save your bookmarks on Xmarks and uninstall FF and then clear out the regitstry with something like CCleaner, then reinstall FF and see if it fixes it.
GL and keep us posted.

As long as I leave Firefox running, I stay logged in . . . all day. If I close it, I am logged out immediately.
Edit: Might want to update to version 3.6.6 as well.

Updated Firefox with no luck. Downloaded the newest version and had no luck either. I was about to do what Cymtyr suggested when I remembered I had installed Chrome a long time ago and it has no problem remembering to stay logged in.
So I'm switching. I've never been too loyal to this or that browser anyway.