We discuss the relation between standard N=2 supergravity with translational
gauging and N=2 supergravities with scalar-tensor multiplets with massive
tensors and Abelian electric charges. We point out that a symplectic covariant
formulation of N=2 supergravity can be achieved just in the presence of tensor
multiplets. As a consequence one can see that the formulation of the N=2 theory
as it comes from IIB flux compactification, which is included in these models,
is equivalent to a non perturbative phase of standard N=2 supergravity. It is
also shown that the IIB tadpole cancellation condition is imposed by
supersymmetry in four dimensions.Comment: 10 pages LaTex, no figure