  We give a detailed and rigorous picture of the mesoscopic conductance
fluctuations in the deep insulating regime (DIR) within the Nguyen, Spivak and
Shklovskii model including spin-orbit coupling (SO). Without SO, we find that
fluctuations of the log-conductance are persistent above a saturation field $%
B_s$, where one has that the log-conductance is approximately a stationary
random process. In contrast, in the SO case the saturation field $B_s$ is
negligible and the stationarity is well realized. We find non-vanishing
disorder fluctuations of the field average of the log-conductance as a
quantitative measure of the lack of ergodicity in the mean square sense. As a
consequence the commonly used criterion to test the ergodicity based on the
equivalence of the variance in disorder and the variance in the field is not
fulfilled. Using the replica approach, we derive the weak localization analogs
of the `cooperon and diffuson.
