OK, well post link to that thread here if you put it somewhere obscure. Just been looking at my physX program where I use dbSetObjectWorldMatrix (virtually straight after doing it i went into DirectX and left DarkGDK alone), and I have noticed that when you move close to and object set with this function, or look at it from an extreme angle, it just disappears. I don't know why this is happening, and changing the project settings hasn't helped. Not really that bothered myself, but it might be an issue for you. It may just be that this functio has never worked, and that's why is undocumented, but that seems strange, as that would mean when making DarkPhysics they had to convert to euler.
EDIT:
I have fixed this problem. it is a very strange fix. basically, I set the position normally before I set the matrix, and it works fine:
NxMat34 getmat = actor->getGlobalPose();
NxVec3 pos = getmat.t;
dbPositionObject((int)actor->userData, pos.x, pos.y, pos.z);
D3DXMATRIX posmat;
float matrixget[16];
getmat.getColumnMajor44(matrixget);
posmat=matrixget;
dbSetObjectWorldMatrix((int)actor->userData, &posmat);
