I've had this problem in the past week. I'm designing a website with sessions, using PHP. On FF, the session id gets lost, and I suspect that it's because the browser is dropping the session_id cookie that gets sent to it, so the session is never recovered (even if it's a named session). If I open Tools-> Options -> Privacy and then click Show Cookies, it's there, but the browser doesn't pick up on it. So the user keeps getting thrown back to the login form.

I did find an error in my code that was making FF not keep the session code. I would have kept looking for an error had ALL the browser lost the session. However the only one that wasn't working the right way for my code was FF which made me think it was FF and not the script. Anyway it is all fixed now. Thanks for the reply.