was printing transposed, also nicer printing.
>>> from mathutils import Matrix
>>> Matrix()
Matrix((1.0, 0.0, 0.0, 0.0),
(0.0, 1.0, 0.0, 0.0),
(0.0, 0.0, 1.0, 0.0),
(0.0, 0.0, 0.0, 1.0))
was...
Matrix((1.000000, 0.000000, 0.000000, 0.000000), (0.000000, 1.000000, 0.000000, 0.000000), (0.000000, 0.000000, 1.000000, 0.000000), (0.000000, 0.000000, 0.000000, 1.000000))