**System Information**
Windows 7 x64, amd 6870 for display and gtx580 3go for rendering, amd drivers: 2013.1206.1603.28764, nvidia drivers: 331.82
**Blender Version**
Broken: 2.69.0 r60995
Worked: no blackbody in previous version
**Short description of error**
Blender crashes when i have a blackbody node on the world with multiple importance sample enabled and then open preview in world option.
**Exact steps for others to reproduce the error**
Open mareck-blackbodynode-world-preview.blend, go to world panel, open preview, it crashes.{F76259}