  In a flat, k=0 cosmology with galaxies that approximate singular isothermal
spheres, gravitational lens image separations should be uncorrelated with
source redshift. But in an open k=-1 cosmology such gravitational lens image
separations become smaller with increasing source redshift. The observed
separations do become smaller with increasing source redshift but the effect is
even stronger than that expected in an Omega=0 cosmology. The observations are
thus not compatible with the "standard" gravitational lensing statistics model
in a flat universe. We try various open and flat cosmologies, galaxy mass
profiles, galaxy merging and evolution models, and lensing aided by clusters to
explain the correlation. We find the data is not compatible with any of these
possibilities within the 95% confidence limit, leaving us with a puzzle. If we
regard the observed result as a statistical fluke, it is worth noting that we
are about twice as likely to observe it in an open universe (with 0<Omega<0.4)
as we are to observe it in a flat one. Finally, the existence of an observed
multiple image lens system with a source at z=4.5 places a lower limit on the
deceleration parameter: q_0 > -2.0.
