I've had this happen a few times, not entirely sure I know why it happens sometimes but not always -- I frequently end up staring at the round Mirror of Galadriel thingy which houses the main menu interface (new game, load game, etc.), but without any options to do something, so I am forced to shut down the client via the program manager and relaunch. One of the things which seems to cause this is sometimes clicking outside the text field when prompted to type a save game name. Grrr...
