  An improved efficient method of calculating the hard bremsstrahlung
correction to e^+ e^- -> 4f for non-zero fermion masses is presented. The
non-vanishing fermion masses allow us to perform the phase space integrations
to the very collinear limit. We therefore can calculate cross sections
independent of angular cuts. Such calculations are important for background
studies. Results are presented for the total and some differential cross
sections for e^+ e^- -> u d-bar mu^- nu and the corresponding hard
bremsstrahlung process. The latter is of particular interest for a detailed
investigation of the effects of final state radiation. In principle, the
process e^+ e^- -> u d-bar mu^- nu gamma is also interesting since it helps to
set bounds on possible anomalous triple and quartic gauge boson couplings
involving photons. The size of mass effects is illustrated by comparing the
final states u d-bar mu^- nu (gamma), c s-bar mu^- nu (gamma) and u d-bar tau^-
nu(gamma).
