  We perform current(I)-voltage(V) measurements on low resistance
superconductor-normal-superconductor arrays in finite magnetic fields, focusing
on the dilute vortex population regime. We observe significant deviations from
predicted behavior, notably the absence of a differential resistance peak near
the vortex de-pinning current, and a broad linear I-V region with an
extrapolated I intercept equal to the de-pinning current. Comparing these
results to an overdamped molecular vortex model, we find that this behavior can
be explained by the presence of a history dependent dissipative force. This
approach has not been considered previously, yet is crucial for obtaining a
correct description of the vortex dynamics in superconducting arrays.
