Mostly - oddly not every time - when I reboot, or start up my laptop, I am not prompted for a password; it goes straight into my desktop. I don't like this one bit. There are other users on my laptop, I'd rather get a greeter that allowed the booting to select their user. I am the only admin user. Sometimes, when I do get a greeter (for just my user), after I login, I get kicked out and have to login again. Again, this is not consistent behaviour.
I can't be certain, but this may have began shortly after I bought an external monitor. Certainly the double login stuff started at that time. It happens now, on occasion, whne I am not plugged into the external monitor.