  We present results from numerical simulations of transport of vortices in the
zero-field cooled (ZFC) and the field-cooled (FC) state of a type-II
superconductor. In the absence of an applied current $I$, we find that the FC
state has a lower defect density than the ZFC state, and is stable against
thermal cycling. On the other hand, by cycling $I$, surprisingly we find that
the ZFC state is the stable state. The FC state is metastable as manifested by
increasing $I$ to the depinning current $I_{c}$, in which case the FC state
evolves into the ZFC state. We also find that all configurations acquire a
unique defect density at the depinning transition independent of the history of
the initial states.
