When using the new 16+ chunks option in minecraft snapshot version 14w30c, I changed the chunk limit to 32. After that, I logged out and went into 1.7.5 and when I tried to enter a server or a world, minecraft would crash. It also showed 32 chunks in the video settings in 1.7.5 and when I slided it down, it went back to the normal options. That also fixed the bug for me.