After playing the game and then leaving it, it will not go to Title screen.

What I expected to happen was...:
Well, I expected it to save the game and go to title screen, obviously ;D

What actually happened was...:
Just kept hanging and not going to title screen.

Steps to Reproduce:
1. Create a game on Mac
2. Wait until it loads
3. Play for a while and make changes to be sure
4. Open the game to lan. My brother didn't see the game appear on lan. Yes we tried multiple times and on some times it worked, but for some reason it stopped working.
5. The hit esc and try to Save and Quit to Title

Only way to kill is with terminal

$ ps aux | grep Minecraft
mirorauhala 92543 1,1 11,6 4389904 485324 ?? S 2:54pm 108:47.15 /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/bin/java .......
$ kill 92543