I found a bug in Blender 2.57b

I was using the node editor to Texture Node and when I delete a node Blender is closed :expressionless:

Is it a bug or I’m doing any bad?

Greetings!

Edit:

I tell we the nodes that I have:
An Input (Texture) connected a Color (RGB Curves) connected an Ouput (Viewer)…
You should load a texture of image.

Tested your setup on my 2.57b 64-bit install. No such problem here.