  We prove by methods of harmonic analysis a result on existence of solutions
for twisted cohomological equations on translation surfaces with loss of
derivatives at most 3+ in Sobolev spaces. As a consequence we prove that
product translation flows on (3-dimensional) translation manifolds which are
products of a (higher genus) translation surface with a (flat) circle are
stable in the sense of A. Katok. In turn, our result on product flows implies a
stability result of time-{\tau} maps of translation flows on translation
surfaces.
