Win 8, GTX 480, Blender 2.68a

When accessing a material node in Python, the `inputs()` collection can normally be (square bracket) indexed either using integer indices or using the string names of the inputs. However, with group nodes, using string indexing does not work, only integer indices work. However, using `find(string)` to get the integer index does work, so `inputs[inputs.find(name)]` works, while `inputs[name]` does not.