Sorry about the brief answer but it was late at night when I read
the question. However, it is easy to see that energy has to be lost to
radiation. The electric fields between the capacitor plates are changing
very rapidly if the wires are low resistance (or resistanceless). A
time-varying electric flux generates a magnetic field (Maxwell's
equations). If you have parallel plate capacitors with circular plates,
you can show by elementary means that the B field generated has a 1/r
spatial dependence; and any E or B field that decreases more slowly than
1/r^2 is a radiation field (i.e. it is carrying energy away from the
source.
Mark
Dr. Mark H. Shapiro
Physics Department
California State University, Fullerton
P.O. Box 6866
Fullerton, California 92834-6866