Minecraft 1.4.3 crashes on Mac running OS X 10.8.2

Put the summary of the bug you're having here
MC crashes when in creative just flying around and working on blocks and world. Semmingly random. After crash it crashes on subsequent launches

What I expected to happen was...:
Describe what you thought should happen here

What actually happened was...:
Describe what happened here

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...
3. ...