Dissociative photoionization of molecular hydrogen and deuterium has been studied using synchrotron radiation and an electrostatic analyzer with a position sensitive detection system for the threshold region of the doubly excited states, 25-45 eV. The Q(1) (1) Sigma(u)(+)(1) autoionizing state plays an important role in the production of fast protons below 30 eV. It is found that, for the incident photon energy 30-40 eV, the dominant process for the production of energetic protons is autoionization of the Q(2), (1) Pi(u)(1) state which preferentially autoionizes to the H(2)(+)2p sigma(u) state rather than to the H(2)(+)1s sigma(g) state. The Q(2) (1) Pi(u)(2) and Q(2) 1 Sigma(u)(+) autoionizing states are alsofound to produce fast protons in this energy region. Above 42 eV, the kinetic energy distributions are dominated by direct ionization to the 2p sigma(u) and 2p pi(u) states of H-2(+).