Download .obj withouth blocking

Hi there,

I am trying to download an .obj file using this code *http://www.everyday3d.com/unity3d/obj/obj.1.2.unitypackage* and it is blocking my game. This is the actual function that blocks the execution.

 public IEnumerator Load(string path) {
     basepath = (path.IndexOf("/") == -1) ? "" : path.Substring(0, path.LastIndexOf("/") + 1);
     WWW loader = new WWW(path);
     yield return loader;
     SetGeometryData(loader.text);
     if(hasMaterials) {
         loader = new WWW(basepath + mtllib);
         yield return loader;
         SetMaterialData(loader.text);
         
         foreach(MaterialData m in materialData) {
             if(m.diffuseTexPath != null) {
                 WWW texloader = new WWW(basepath + m.diffuseTexPath);
                 yield return texloader;
                 m.diffuseTex = texloader.texture;
             }
         }
     }
     
     Build();
 }

I call that function like this:

 void Start ()     {
     obj = new OBJ("monkey");
     StartCoroutine(obj.Load(path));
 }

And once the code gets to the first yield return it blocks until everything gets downloaded and processed. I would like to get some advice on how to structure the code so I can avoid that blocking. I have been reading about StarCoroutine functions as well as yield return statements and there must be something obvious I am missing.

Thanks in advance