  We analyse the effect of general brane kinetic terms for bulk scalars,
fermions and gauge bosons in theories with extra dimensions, with and without
supersymmetry. We find in particular a singular behaviour when these terms
contain derivatives orthogonal to the brane. This is brought about by
$\delta(0)$ divergences arising at second and higher order in perturbation
theory. We argue that this behaviour can be smoothed down by classical
renormalization.
