linpack and eispack are vestigial. They were folded into lapack, which is the "one true package" now (e.g., http://en.wikipedia.org/wiki/EISPACK). The situation here is really not complicated.

scalapack is a different animal entirely. It's a parallel version of lapack (via MPI) so should not be expected to duplicate lapack results because partitioned algorithms will be used. But if you're using scalapack, you know that already.