[ODE] Quaternion/Rotation problem?

[David Jung]

If I execute this code: 

  q[1] = 0.00074993; q[2] = 0.000499856; q[3] = 0.000499856; q[0] = 
0.999999; // x,y,z,w
  dBodySetQuaternion(bodyID, q);
  const dReal* R = dBodyGetRotation(bodyID);
  dBodySetRotation(bodyID, R);
  const dReal* oq = dBodyGetQuaternion(bodyID);
  printf("Got back %5.3f %5.3f %5.3f %5.3f\n",oq[1],oq[2],oq[3],oq[0]);

I get:
Got back 0.001 0.000 0.000 1.000

which is not the same Quaternion (and doesn't represent the same
orientation - or even a valid one [shouldn't it be unit length?]).

Is it me or is there something amiss here?
Cheers,
-David.