  We consider viscosity and thermal conductivity as dissipation mechanisms to
derive a general dispersion relation for MHD waves propagating in a homogeneous
plasma. We show that the actual dispersion relation for MHD waves in a
homogeneous medium must be six-order. The finding is in agreement (except some
coefficients) with the results of Porter et al. (1994) but it is in
disagreement with the previous results obtained by Kumar et al. (2006). We also
discuss in detail differences between our approach and those considered by
other authors.
  Accepted, BASI
