Unable to create new worlds/play in older worlds in the new snapshot, they turn pitch black.

After a couple of days of not playing Minecraft, I came back and I loaded up my creative world. I opened and it was all pitch black. I checked if I was in the void but no??? I opened another world and the same thing happened... My graphics card is an Nvidia GeForce 7600 GT/PCIe/SSE2 (you can see that on one of the screenshots), and I'm running a Windows 7 computer.