Okay what's going on here... after getting the Live update, I can't play a 2-player game of UMK3! When I press "A" on the second controller, it prompts me to sign into Live again. If I press "B," the game just advances one frame and then prompts me again, so I can't cancel out. If I press "A" to sign in again, I get booted back to the UMK3 title screen, with the select screen music still playing in the background! I tried restarting the xbox and starting with Player 2, but either way, as soon as another player joins in, I get all this weirdness!
Has this happened to anyone else? I was able to do a normal 2-player game before. Last time I did that was before the Live update.
EDIT: Never mind, I made an extra guest profile and used that to sign in Player 2. It was just confusing, because I could swear I did 2 Players before without it ever asking for a guest account...