  The current-voltage characteristics of Au/InOx/Pb tunnel junctions exhibit
peculiar zero-bias anomalies. At low temperature the zero-bias resistance
attains values that are smaller than the normal state resistance by a factor
that often esceeds 2. The width of this anomaly increases with the thickness of
the InOx layer. The possibility that these features arise from the nature of
the barrier being an Anderson insulator is discussed.
