I use Firefox and this has happened to me a few times. It's not that rare of an occurrence but it does happen from time to time. However, it has never happened to me so far after I play the first T50 match. If I can play a T50 match the first time, this problem never occurs if I stay connected and play during the same seesion.
This problem only happens on the first T50 match attempt I try after I have logged in for me. If it's waiting for an opponent for longer than 3-5 seconds, it will never find one, no matter if I click back and try again. But if I reload the page and log back in, it works.
I use to get disconnected a lot before Nov/Dec, but ever since then (I don't know what zanz did), I rarely now ever get disconnected from the game server. But this T50 problem still shows up once in a while. Strange!