The Collada specification explains that an instance_controller can have skeleton entries to define which subset of a joint hierarchy shall be searched to find the joints, like:

Code :
<node>
  <instance_controller url="#skin">
    <skeleton>#root</skeleton>
    <bind_material>...</bind_material>
  </instance_controller>
</node>
But it does not tell what to do when no <skeleton> is available. For example the <authoring_tool>FBX COLLADA exporter</authoring_tool> omits the skeleton:

Code :
<node>
  <instance_controller url="#skin">
    <bind_material>...</bind_material>
  </instance_controller>
</node>

When i parse such Collada code with the OpenCollada framework, then i get "Sax FWL Error: Could not resolve sid ..." for every joint in the Joint hierarchy and the Object is not skinned.
However Maya-2013 can read the collada files correctly with its native Collada Importer.

Is this a bug in OpenCollada, or a missing feature ? Or is that a violation of the specification by the FBX Collada exporter ?