Put the summary of the bug you're having here
Encountered bug where a single chunk won't load in the Nether. Since finding this chunk, sometimes entering or exiting the Nether causes game crashes.
Environment
OS: Mac OS X (ver 10.8.2, arch x86_64)
Java: 1.6.0_43 (by Apple Inc.)
Launcher: 0.7 (Dev) (bootstrap 2)
Duplicate of MC-2545.