I've seen a problem very similar to this before, theres often several possible solutions to a single matrix when converting to eular angles
From memory the newton matrix is laid out at 90 degrees to an opengl one 0=0 1=4 2=8....
matrix to eular is a potential source of problems and computationally not cheap
and the same for eular to matrix
I'd have a go at directly converting from a newton matrix to a minib3d one.
the newton matrix will be missing the scale data from the minib3d one and it might only be a rotation matrix
Let me know if you need any more help.
From memory the newton matrix is laid out at 90 degrees to an opengl one 0=0 1=4 2=8....
matrix to eular is a potential source of problems and computationally not cheap
and the same for eular to matrix
I'd have a go at directly converting from a newton matrix to a minib3d one.
the newton matrix will be missing the scale data from the minib3d one and it might only be a rotation matrix
Let me know if you need any more help.