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".