Your Hero sprite is a 2 frame animation. The collision box on both frames doesn't match up, take a look at the collision box on frame 1.
That's your answer ;).
<img src="http://content.screencast.com/users/ArcadEd/folders/Jing/media/3771d9e8-c7d5-4be0-aaf7-759f2e6b454a/2013-05-29_1432.png" border="0" />