Occassionally unable to connect to game?

Right after pick a champ and loading screen happens, the screen goes dark (right before the portraits) and says "unable to connect to game" with giving me the option to retry or cancel.

both options fail, and even closing the cilent doesn't work. restarting my computer doesn't work, and i dont recieve any penalties after the inevitable remake happens.

my connection is fine and i even delete the game config file sometimes. why does this happen? i can connect to any other game fine its just this sometimes happens....