It seems like the login session expires too quickly. It used to be that once every couple of days, firing up the launcher would require that I re-enter my password. Now it seems like the login session expires a lot more quickly. For example, today I fired up the launcher and had to reenter my password. I didn't start the main game until less than 2 hours later, but when I did, I couldn't login to a multiplayer server without quitting and starting it all again.