Kaon vs. Bottom: Where to look for a general MSSM?

We analyze CP violation and Flavor Changing effects in a general Minimal Supersymmetric extension of the Standard Model with arbitrary non-universal soft-breaking terms. We show that, in this conditions, large FCNC effects are naturally expected in the Kaon system, even in the absence of quark-squark flavor misalignment. On the other hand, the B system is only sensitive to new supersymmetric contributions if the non-universality implies, not only different soft term for the three generations but also the presence of a quark-squark misalignment much larger that the corresponding CKM mixing. The only exception to this rule are processes where the chirality changing contributions proportional to tan beta are leading (for instance b -> s gamma).