  We study the hidden sector effects to the mass renormalization of a simplest
gauge-mediated supersymmetry breaking scenario. We point out that possible
hidden sector contributions render the soft scalar masses smaller, resulting in
drastically different sparticle mass spectrum at low energy. In particular, in
the ${\bf 5}+\bar{\bf 5}$ minimal gauge mediated supersymmetry breaking with
high messenger scale (that is favored by the gravitino cold dark matter
scenario), we show that stau can be the next lightest superparticle for
moderate values of hidden sector self coupling. This provides a very simple
theoretical model of long-lived charged next lightest superparticles, that
imply distinctive signals in ongoing and upcoming collider experiments.
