Notes/Domino 4 and 5 Forum

I have a problem with shedule replication.
I have an office in china, and i'm connect to this office throught a vpn behind a firewall.

I can ping this office with the Lotus notes server.
The VPN work properly and is already up.
I can connect to the China Lotus Notes Server and
I launch a manual replication. it work
I can open database,close,save, modify....

But the shedule replication task doesn't work.
The time connection is 0 and
the error message is "Unable to replicate Directory\base.nsf"



Thanks for help