Updating a table on local machine from remote linux server

I have a postgresql 7.5.1 database with one table on a SuSE 9.2 server. 
I also have the same database on my windowsxp laptop. I done a 
backup-restore operation to get the original database on the windows 
machine, but seem I cannot update using that. It comes up with duplicate 
primary key errors.

I have tried MS Access, but it does strange things, like not updating 
the values that have changed in a table on a make table query and not 
updating the access table with an update query because it is locked by 
access itself. OOo Base is not quite ready yet to do anything except 
connect to the database and run queries but no update or append queries 
as you cannot link two databases at the same time.

So, how is the best way to do an update-append from one table in a 
postgresql database on a remote machine to a postresql database with the 
same table with old values?

I have PgAdmin running also and can connect to both databases.

Any suggestionsd would be appreciated. I only need to do the one table 
really.

Art