We review the theory and present status of the proton spin problem with emphasis on possible gluonic and sea contributions. We discuss the possibility of a J=1 fixed pole correction to the Ellis-Jaffe sum rule for polarized deep inelastic scattering. Fixed poles in the real part of the forward Compton scattering amplitude have the potential to induce subtraction constant corrections to sum rules for photon--nucleon scattering.

PACS numbers: 11.55.Hx, 13.60.Hb, 13.88.+e