  We discuss theoretical and phenomenological aspects of the use of boson
propagators with energy-dependent widths in predictions for high-energy
scattering processes. In general, gauge invariance is violated in such
calculations. We discuss several approaches to restore gauge invariance,
necessary for a reliable result. The most promising method is the addition of
the relevant parts of the fermionic corrections, which fulfills all Ward
identities. The numerical difference between this and other approaches is
studied. A number of recommendations are given for LEP2 computations.
