Datatype misrepresentation DTS with SQL Server

(I sincerely apologize if this is has been covered here - I didn't have
much luck searching the archives)

I'm trying to use the "Import and Export Data" (DTS) tool included with
MS SQL Server to push data to a PostgreSQL 7.1.3 database via an ODBC
connection. Everything works great, except if I try to use the
bigint/int8 data type for columns on the PostgreSQL side. DTS
incorrectly sees the int8 datatype as "char" and therefore ties to shove
a space-padded representation of the integer into the table. PostgreSQL
doesn't like it.

The integer/int4 datatype doesn't cause this problem, but I will be
inserting more rows than the int4 datatype can count (I want a bigint
primary key).

I don't know any way around this problem, and DTS is kind of a
requirement for the project.

Thanks in advance for any help you can provide.

-MW