The recent observation of an inflection point in the temperature dependence
of the in-plane magnetic field dependence (lambda_ab) is investigated within a
two-band model with coupled order parameters of different symmetries. While the
dominant order parameter has d-wave symmetry, the smaller one is of s-wave
symmetry. Superconductivity is robust in the d-wave channel and induced via
interband interactions in the s-wave subsystem.Comment: 10 pages, 4 figure