  We report new measurements of inclusive pion production from frozen-spin HD
for polarized photon beams covering the Delta(1232) resonance. These provide
data simultaneously on both H and D with nearly complete angular distributions
of the spin-difference cross sections entering the Gerasimov-Drell-Hearn (GDH)
sum rule. Recent results from Mainz and Bonn exceed the GDH prediction for the
proton by 22 microbarns, suggesting as yet unmeasured high-energy components.
Our pi0 data reveal a different angular dependence than assumed in Mainz
analyses and integrate to a value that is 18 microbarns lower, suggesting a
more rapid convergence. Our results for deuterium are somewhat lower than
published data, considerably more precise and generally lower than available
calculations.
