  We study the phase diagram of an electron on a square lattice in a transverse
magnetic field. Using a renormalization scheme, we show that the inequality of
the two next-nearest neighbor couplings destroys the fat critical regime above
the bicritical line and replaces it with another reentrant extended phase.
Furthermore, the universal strange attractor describing self-similar
fluctuations of the localized phase is replaced by a new fixed point. The
reentrant extended phase and the new fixed point of the localized phase belong
to the universality class of an anisotropic triangular lattice.
