In 1985, Harmuth wrote that Maxwell's equations are incompatible with causality, and overcame the problem by adding a term for magnetic dipole currents, and as a consequence the problem of infinite zero-point energy and renormalization disappears. At least according to Harmuth's book:
Calculus of finite differences in quantum electrodynamics By Henning F. Harmuth, Beate Meffert
The foreword is readable at http://books.google.com/books?id=EQFENquY6fwC
Are Harmuth's modifications generally accepted by the physics community as a more accurate description of reality than the unmodified equations ?