You have been disconnected from the login server.

I responded recently to an identical thread with my story of how my laptop makes it to the login screen just fine, while my older desktop gets that message from 1~3 times before being able to get in. Recently, I've had to rely on my cell phone tethered to have internet access resulting in the same desktop (on wireless dongle) unable to get in after 10+ tries. I disconnected all other devices tethered (laptop) and tried again and it only took three times to get in, I have a sneaking suspicion it has something to do with hardware and internet speed/connection. Unfortunately, that's all the information I can give. Someone did suggest disabling that Pando Media Downloader if that is running in the background.