Operating system and graphics card
i use OSX Maverick on my macbookpro 13" 2010. The graphic card used is NVIDIA Geforce 9400M 256MB. My processor 2.53 GHz Intel Core 2 Duo with 6 GB 1067 MHz DDR3 of RAM
Broken: I used 2.70a and when i try it in 2.71 it still can't render
Short description of error
At first i can render it but after i make some change and i try to render it, it just stopped rendering after 2 tiles.
Exact steps for others to reproduce the error
Based on a (as simple as possible) attached .blend file with minimum amount of steps