collada, 3ds, skeletons, and pivot matrices

Hey folks, I'm goofing around w/ collada and 3ds max atm, but I'm having some trouble interpreting some of the data exported. I was wondering if someone here could explain a little of it to me, particularly w/ finding the pivot point. I generate a biped skeleton (no mesh), put it in the base pose, and export it via ColladaMax. Here is a snip of some of the data it exports:

      <node id="Bip01-node" name="Bip01" sid="Bip01-node" type="JOINT">
        <matrix>0.000001 1.000000 0 0 -1.000000 0.000001 0 0 0 0 1.000000 0.542000 0 0 0 1.000000</matrix>
        <node id="Bip01-node_PIVOT" name="Bip01_PIVOT" type="NODE">
          <matrix>0.002427 0 0 0 0 0.002427 0 0 0 0 0.002427 0 0 0 0 1.000000</matrix>
        </node>
        <node id="Bip01_Pelvis-node" name="Bip01_Pelvis" sid="Bip01_Pelvis-node" type="JOINT">
          <matrix>0 1.000000 -0.000001 0 -0.000001 0.000001 1.000000 0 1.000000 0 0.000001 0 0 0 0 1.000000</matrix>
          <node id="Bip01_Pelvis-node_PIVOT" name="Bip01_Pelvis_PIVOT" type="NODE">
            <matrix>0.121359 0 0 0 0 0.121359 0 0 0 0 0.097087 0 0 0 0 1.000000</matrix>
          </node>

How do you find the pivot point? Is it the translation portion of the main bone node's matrix? If so, then what are the pivot nodes for? The matrices for these pivot nodes are scaling matrices, not translations. Is maybe the translation portion of the main bone node's matrix scaled by the pivot node's matrix? There are lots of permutations. I figured I'd ask around first.