  A phenomenological calculation from threshold to 800 MeV of the initial
proton beam energy is presented to describe recent data on the reaction pp -->
(pp)_S-wave pi^0 with a low energy cut on the final state diproton excitation
energy. A strong forward dip is obtained in the differential cross section as
in the data from COSY at 800 MeV, although the absolute value of the forward
cross section is too low. Earlier low energy data from CELSIUS are reasonably
well reproduced. In the unexplored energy interval between these two
experiments the model predicts a spectacular energy dependence both in the
forward direction and in the angle-integrated cross section.
