  We show that the observed K-velocities and periodicities of AM CVn can be
reconciled given a mass ratio of 0.22 and a secondary star with a modest
magnetic field of surface strength of order 1 Tesla. We see that the new mass
ratio implies that the secondary is most likely semi-degenerate. The effect of
the field on the accretion disc structure is examined. The theory of precessing
discs and resonant orbits is generalised to encompass higher order resonances
than 3:2 and shown to retain consistency with the new mass ratio.
