  We compute the one-loop worldsheet S-matrix for the superstring in AdS(3) x
S(3) x T(4) supported by a combination of RR and NSNS flux in the massive
sector. In the appropriate regularization scheme it agrees with the S-matrix
found from symmetry considerations including the proposed dressing phases. As
previously observed in other cases the massless modes decouple from the
calculation of one-loop massive mode scattering. We also calculate the
correction to the dispersion relation at two loops in the Near-Flat-Space limit
and find agreement with a proposal for the form of the exact dispersion
relation for the massive modes. Somewhat surprisingly the massless modes again
decouple from the calculation (in a suitable regularization scheme). We also
compute the correction to the dispersion relation for the massless modes and
compare to a suggestion for the exact dispersion relation, finding a small
discrepancy. The corresponding calculations for AdS(5) x S(5) and AdS(2) x S(2)
x T(6) are used for comparison.
