Before I tell about the bug, I want people to know: This affects earlier versions of 1.4 down to about 1.4.2.

So, with this bug, basically what happens is, I create a world and I spawn in, and you know where I spawn? Underground. I'm not talking about like in a cave, I mean completely underground. I have to break a block to get my bearings, and I look and I'm completely submerged. Half of me is inside of the block I am supposedly standing on, and I am surrounded by usually dirt or stone. I break out and find myself where I was supposed to spawn.