We analyze the action of the spectral flows on N=2 twisted topological
theories. We show that they provide a useful mapping between the two twisted
topological theories associated to a given N=2 superconformal theory. This
mapping can also be viewed as a topological algebra automorphism. In particular
null vectors are mapped into null vectors, considerably simplifying their
computation. We give the level 2 results. Finally we discuss the spectral flow
mapping in the case of the DDK and KM realizations of the topological algebra.Comment: The presentation of the results has been very much improved. Some
references have been adde