  Two approaches to extend Hardy's proof of nonlocality without inequalities to
maximally entangled states of bipartite two-level systems are shown to fail. On
one hand, it is shown that Wu and co-workers' proof [Phys. Rev. A 53, R1927
(1996)] uses an effective state which is not maximally entangled. On the other
hand, it is demonstrated that Hardy's proof cannot be generalized by the
replacement of one of the four von Neumann measurements involved in the
original proof by a generalized measurement to unambiguously discriminate
between non-orthogonal states.
