I received the 1.7.2 update of Minecraft, and I tried to play one of my worlds I had created a while before the update. I start looking through the new blocks in creative mode, decide to place torches throughout my world, then as I select the torch, the whole world turns black, and all the blocks turn black. As i quit and reload the world, the world looks normal, but as soon as I switch or place a block, the problem happens again. It doesn't seem to happen on worlds I create after the newest update.