Object function has no method 'execute' when trying the backbone_example module

I finally got something a little bit better.
I changed the return template.execute(vars); to simply return template(vars); (instead of the call).

Next, i modified the theme_backbone_example_node_template function. There is an added verification "typeof(node) != "undefined" && ".

return '<% if (typeof(node) != "undefined" && node.title && node.body) { %><h2><%= node.title %></h2><div><%= node.body.und[0].safe_value %></div><% } %>';

Now there is no more javascript errors on the page but if I try to load the node 1 which exists I got a 404 error:
"GET http://localhost/backbone/rest/node/1.json 404 (Not Found) "
It should be http://localhost/drupal_backbone/rest/node/1.json but if I try with this url I also get a 404.
I installed the drupal in a subdirectory, so the url should be http://localhost/drupal_backbone/backbone/rest/node/1.json

I've found a way to get correct path without modifying the backbone option. I modified the backbone_init function so that it include the base_path:

function backbone_init() {
  global $base_path;
  drupal_add_library('backbone', 'drupalbackbone-services');
  $backbone_settings = array(
    'backbone' => array(
      'endpoint' => $base_path . _backbone_variable_get('endpoint'),
    ),
  );
  drupal_add_js($backbone_settings, 'setting');
}

Now I'm back to square 1 since nothing get displayed if I try to load the node 1. (the json is loaded)
So it's the return template.execute(vars); correction which is wrong.
I tried without success:

return template.call(vars);
return template.call(this, vars);
return template(vars);

Any idea?

Ok thanks.
Just in case, the commit where this bug was introduced: http://drupalcode.org/project/backbone.git/commitdiff/288031693ae325ac8c...

In fact there is a difference of how the "variables" value is constructed. The render function was using this before:
variables = this.model.toJSON();

This returned an object with a 'node' attribute.

But now the variables = this.model.renderAttributes(); return an object with only the node properties (the equivalent of variables.node).

So here is a first patch that fixes the example.

For underscore template rendering it changed return template.execute(vars); to return template(vars);

I've also added the $base_path in the endpoint url. It's not really specific to this issue so tell me if you would like that I reroll the patch without this modification.

The last thing is that I changed the theme_backbone_example_node_template function so that it directly access the title variable (title instead of node.title).