  In the diquark-quark model of the nucleon including scalar and axialvector
diquarks we compare solutions of the ladder Bethe-Salpeter equation in the
instantaneous Salpeter approximation and in the fully covariant (i.e.
four-dimensional) treatment. We obtain that the binding energy is severly
underestimated in the Salpeter approximation. For the electromagnetic form
factors of the nucleon we find that in both approaches the overall shapes of
the respective form factors are reasonably similar up to $Q^2 \approx 0.4$
GeV^2. However, the magnetic moments differ substantially as well as results
for the pion-nucleon and the axial coupling of the nucleon.
