We consider the Born-Infeld action for symmetry-preserving, orientable
D-branes in compact group manifolds. We find classical solutions that obey the
flux quantization condition. They correspond to conformally invariant boundary
conditions on the world sheet. We compute the spectrum of quadratic
fluctuations and find agreement with the predictions of conformal field theory,
up to a missing level-dependent truncation. Our results extend to D-branes with
the geometry of twined conjugacy classes; they illustrate the mechanism of flux
stabilization of D-branes.Comment: 13 pages, 1 figure. Comment and references adde