  V(I) characteristics have been performed in a monocrystalline microbridge of
$Bi[Pb]-2212$. The vortex phase diagram has been greatly investigated. Linear
but non-ohmic Voltage(Current) (V(I)) curves with well defined critical current
have been observed. A departure from this behavior is observed near the peak
effect where an out of equilibrium high threshold current can be stabilized. At
high temperature, the critical current persists in the "liquid" state despite
the dissipation at the lowest bias. Some implications of these results are
discussed. In particular, it is proposed that the surface disorder, rather than
the bulk disorder, is responsible for the vortex pinning in this sample.
