connection to Access tables

I am running PostgreSQL on a linux box (Red Hat).  I have set everything up
to successfully communicate with MS-Access (which is on a Windows 98 machine
on my network).  From Access I can import tables from PostgreSQL
successfully.  I can also link to PostgreSQL tables and update them from
Access.  What I really want to do though is repeatedly export existing
Access tables (which are constantly being updated by our software) to
PostgreSQL.  When I try to do this the table name appears on the Linux box
but the table isn't really set up.  Also, once the table name is there I
can't export again or I get the error that the table already exists.  Should
I be able to do this?  If not, what's the best way to keep the up-to-date
info from the Access tables current in PostgreSQL.  Any ideas or tips would
be greatly appreciated.                        Thanks,                            Jenni Jaeger