Anytime I open a game in the minecraft launcher, I am able to take literally 1 step before the keyboard stops working. I am unable to quit the program through the program and have had to force quit it.

What I expected to happen was...:
I should be able to walk around and jump and do other things.

What actually happened was...:
I can't move, and am limited to whatever is within reach around me.

Steps to Reproduce:
1. launch minecraft on a Mac running OS x 10.8.3
2. attempt to play