  We report spin-dependent electron density of states (DOS) studies of
ultra-thin superconducting Al and Be films in high parallel magnetic fields.
Superconductor-insulator-superconductor (SIS) tunneling spectra are presented
in which both the film and the counterelectrode are in the paramagnetic limit.
This SIS configuration is exquisitely sensitive to spin mixing and/or spin flip
processes which are manifest as DOS singularities at eV = 2Delta +- eV_z. Both
our Al and Be data show a well defined subgap peak whose magnitude grows
dramatically as the parallel critical field is approached. Though this feature
has previously been attributed to spin-orbit scattering, it is more consistent
with fluctuations into a field induced mixed-spin state.
