  The Gribov ambiguity problem is studied for compact lattice QED within the
Lorentz gauge. In the Coulomb phase, Gribov copies are mainly caused by double
Dirac sheets and zero-momentum modes of the gauge fields. Removing them by
(non-) periodic gauge transformations allows to reach the absolute extremum of
the Lorentz gauge functional. For standard Lorentz gauge fixing the Wilson
fermion correlator turns out to be strongly effected by the zero-momentum
modes. A reliable fermion mass estimate requires the proper treatment of these
modes.
