80:  Why does ispell sometimes ignore the local dictionary?
  
  You need to update the version of Ispell to 2.0.02.  (Or you can switch to
  version 3.0 which is still in beta-testing.)  A patch is available via
  anonymous FTP (archive.cis.ohio-state.edu: /pub/gnu/ispell/patch2.Z).
  
  You also need to change a line in ispell.el from:
  
    (defconst ispell-version "2.0.01") ; Check against output of "ispell -v".
  
  to:
  
    (defconst ispell-version "2.0.02") ; Check against output of "ispell -v".