We reexamined the strong compositional dependence of the conductivity &sgr; discovered by Ferrieretal. in TemT12films. We found the optical gap and the activation energy of &sgr; to be independent of m. At low T an extrinsic conduction occurs near m=2.5 and 3.5. The defect states causing this are removed by annealing in clean films. Annealing is prevented by one atomic percent oxygen.