We consider effects of a long-wavelength disorder potential on the Zero
Conductance State (ZCS) of the microwave-irradiated 2D electron gas. Assuming a
uniform Hall conductivity, we construct a Lyapunov functional and derive
stability conditions on the domain structure of the photo-generated fields. We
solve the resulting equations for a general one-dimensional and certain
two-dimensional disorder potentials, and find non-zero conductances,
photo-voltages, and circulating dissipative currents. In contrast, weak white
noise disorder does not destroy the ZCS, but induces mesoscopic current
fluctuations.Comment: 4 pages, 2 colour figure