  The nature of the dark components (dark matter and dark energy) that dominate
the current cosmic evolution is a completely open question at present. In
reality, we do not even know if they really constitute two separated
substances. In this paper we use the recent Cosmic All Sky Survey (CLASS)
lensing sample to test the predictions of one of the candidates for a unified
dark matter/energy scenario, the so-called generalized Chaplygin gas (Cg) which
is parametrized by an equation of state $p = -A/\rho_{Cg}^{\alpha}$ where $A$
and $\alpha$ are arbitrary constants. We show that, although the model is in
good agreement with this radio source gravitational lensing sample, the limits
obtained from CLASS statistics are only marginally compatible with the ones
obtained from other cosmological tests. We also investigate the constraints on
the free parameters of the model from a joint analysis between CLASS and
supernova data.
