Migrating databases from MS SQL Server to PostgreSQL

Hi,

I'm trying to migrate one of our MS SQL databases to Postgre, but have
encountered a little problem. I thought that the best way to do it was
to use Postgre ODBC drivers to transfer data from SQL Server from a
DTS. The only tables that I can't transfer have some columns of text
type. I can't change it to varchar, because some fields can have more
than 8040 characters (SQL Server's limit). When executing the DTS,
I've got the following error : "Data for source column 9 is too large
for the specified buffer size". Column 9 is the first column with text
type.
Do you have an idea on how I could avoid this, or another way to
import data ? I've also tried to export my tables in text format and
import with postgre's COPY, but some fields have carriage return
included (for web pages) wich doesn't make it easy.

Thanks,
Doobie