We've all seen it. The random dungeon group times out because one member doesn't ready up. This weekend I got to be that guy. I was playing in the same room with another party member. This time I was the tank. As I'm waiting for the queue to pop, he says, "Are you going to hit ready?"
I say, "I don't have a prompt."
He says, "Everyone else has readied up."
Sure enough, on his screen the party is waiting on a tank, on mine, no prompt, no notification. The message in the quest area still says I'm queued, and when I go to look at the party menu, the game kicks me. I wasn't porting, my internet wasn't unstable, the other player using the same router didn't lose connection or get kicked from the game. When I logged back in, we were able to queue almost immediately with no further problems. Go figure.