When starting a new game, I have a tendency to alt-tab out of SC2 while the game loads. It seems like when I reopen SC2 (as non-host) and there is a menu open, I appear to encounter an issue where clicking Game Length, Difficulty, Order, etc. causes the menus to not appropriately close. My best guess is that the problem arises when I choose an option after the host makes his selections.
This issue is certainly a result of my laziness, but I don't want to play the game with a modal popup showing for the length of the game.