At http://www.netlib.org/scalapack/complex16/pzheev.f it says
* PZHEEV computes selected eigenvalues and, optionally, eigenvectors
* of a real symmetric matrix A by calling the recommended sequence
* of ScaLAPACK routines.
But the type of the matrix is
COMPLEX*16 A( * )
Based on the naming scheme I think A is supposed to be complex Hermitian instead of real symmetric.