We calculate the low-energy effective action of massless and massive complex linear superfields coupled to a massive U(1) vector multiplet. Our calculations include superspace higher-derivative corrections and therefore go beyond previous results. Among the superspace higher derivatives, we find that terms that lead to a deformation of the auxiliary field potential and may break supersymmetry are also generated. We show that the supersymmetry breaking vacua can only be trusted if there exists a hierarchy between the higher-order terms. A renormalization group analysis shows that generically a hierarchy is not generated by the quantum corrections.