Backup exec v 9.0

I have a Netware 5.1 server with SP5...
When i try to backup files on a server i see in the job log an error reading
: Ndmp error ndmp_connect_error (23). unable to establish connection

Between the data server and the media server. The supplied username and

password for the device may be incorrect.

But i know that the password/username aint wrong, i can get access to
make selections. The user have admin rights. I use IP but also have IPX
bound to the NIC.
and the remote NW 5.0 server i`m trying to backup also have IP/IPX.
The agent on the server looks like it runs just fine with no error messages
on startup.
The remote server is written in the file NDMPSVRS.DAT on the media server
with name and IP.

anyone have an idea what can be wrong ??