Looks like Halo's code there can help a bit for B3D. From that thread though ... I want to know how B3D's work different from others? I'm thinking someone is getting quaternions confused with axis-angle rotation which can also be written as a 4 component vector:
http://homepages.inf.ed.ac.uk/rbf/CVonline/LOCAL_COPIES/AV0405/REDSTONE/AxisAngleRotation.html
http://homepages.inf.ed.ac.uk/rbf/CVonline/LOCAL_COPIES/AV0405/REDSTONE/AxisAngleRotation.html