  We have described electron spin dynamics in the presence of the spin-orbit
interaction and disorder using the spin-density matrix method. Exact solution
is obtained for an arbitrary 2D spin-orbit Hamiltonian and arbitrary smoothness
of the disorder potential. Spin current depends explicitely on the disorder
properties, namely the smoothness of the disorder potential, even in the
ballistic limit when broadening by scattering is much smaller than the
spin-orbit related splitting of the energy spectrum. In this sense universal
intrinsic spin current does not exist.
