  We present six years of new radial-velocity data from the Anglo-Australian
and Magellan Telescopes on the HD 73526 2:1 resonant planetary system. We
investigate both Keplerian and dynamical (interacting) fits to these data,
yielding four possible configurations for the system. The new data now show
that both resonance angles are librating, with amplitudes of 40 degrees and 60
degrees, respectively. We then perform long-term dynamical stability tests to
differentiate these solutions, which only differ significantly in the masses of
the planets. We show that while there is no clearly preferred system
inclination, the dynamical fit with i=90 degrees provides the best combination
of goodness-of-fit and long-term dynamical stability.
