mpi too large (63451 bits) Error

Nguyen Tuan-ATN014
Fri Feb 22 07:56:01 2002

I am trying to move this pgp system off of unix and onto nt with gpg.  While at the same time keep all of the public, private, and secret keys.  I've managed to import the keys but when I decrypt the existing unix files on nt, i get this error: 
mpi to large and 
a windows pop up saying gnupg has generated an error and will be closed.  

Any clues?