Blender 2.5.4 crashing os x during render?

i’ve been trying to learn blender, starting with the 2.53 release and now updated to 2.54. unfortunately i don’t have experience with 2.4 to compare behavior, but for the past 2 nights i have set up a render for a simple(?) scene and the next day my computer’s displays will not “wake up”. when i force my machine to restart, i am presented with a message that os x crashed before the restart.


  • mac pro 3.0 quad, 10.5.8, 10gb ram, ati 4870
  • blender 2.54
  • single object in .blend, w/ glass-like material applied w/ refraction index, defocus node, rotating over 50 frames

blender seems to be reasonably stable thus far with what i have thrown at it, this behavior is surprising. any thoughts on what could be contributing to this crashing behavior? i’m not running anything else computationally significant, and this only seems to occur if i leave blender rendering for a few hours.