With facebook, i've noticed that sometimes i'll log in and have chat messages from my last visit that I didn't get while I was logged in, so i'm thinking that chat must show you as available for a short amount of time after you click logout. Also, sometimes i'll message people and they won't write back but will sign off shorty after i send them the message, so I wonder if this is also part of that problem. Anybody know how long you're name stays on available on chat after you click logout?