  In the case with a large splitting between the squark and slepton masses, the
supersymmetric identities which enforce the equality of the gauge and gaugino
couplings are violated in the effective theory below the squark mass threshold.
We compute the full one-loop (s)quark corrected slepton production
cross-sections. We find that the one-loop corrected slepton production
cross-sections can depend on the squark mass strongly, up to 9%
*log_{10}(M_{\tilde{Q}}/m_{\tilde{l}}). We investigate the squark mass
sensitivity of the slepton cross-section measurements at a future linear
collider. For sneutrino production accessible at \sqrt{s}=500 GeV there can be
sensitivity to squark masses at or larger than 1 TeV.
