  C. Jantzen has defined a correspondence which attaches to an irreducible
representation of a classical $p$-adic group, a finite set of irreducible
representations of classical $p$-adic groups supported in a single or in two
cuspidal lines (the case of the single cuspidal lines is interesting for the
unitarizability). It would be important to know if this correspondence
preserves the unitarizability (in both directions). The main aim of this paper
is to complete the proof started in the previous paper of the fact that if we
have an irreducible unitarizable representation $\pi$ of a classical $p$-adic
group whose one attached representation $X_\rho(\pi)$ supported by a cuspidal
line, has the same infinitesimal character as the generalized Steinberg
representation supported in that line, then $X_\rho(\pi)$ is unitarizable.
