VMS Help CC, Messages, FUNCMIXPTR  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 Message        <Context> function types differ because this
                declaration specifies "<type1>" and a previous
                declaration specifies "<type2>".

 Description    A function redeclaration differs from an earlier
                declaration of the same function because the pointer
                size of one of the arguments or the return result is
                different.

 User Action    Use the same pointer size for all declarations of the
                function.