--- Operating System, Graphics card ---
Nvidia 8800 gtx

--- Blender version with error, and version that worked ---
2.68a windows 64bit ( on Windows 7 64bit Home Edition )

--- Short description of error ---
When I try uv_on_emmiter , blender just close.

--- Steps for others to reproduce the error (preferably based on attached .blend file) ---

Simply use this: http://www.blender.org/documentation/blender_python_api_2_68_5/bpy.types.Particle.html?highlight=uv#bpy.types.Particle.uv_on_emitter
Delete Default cube
Create a plane
Add a particles systems
Add a UV set to the plane

Run this command in the console:

bpy.context.object.particle_systems['ParticleSystem'].particles[0].uv_on_emitter()

Blender just close really fast.