[Samba] mount_smbfs can't get server address

[ben]

i am running freebsd 4.6.2 
i am using this command to mount a windows share from windows xp
mount_smbfs //user at server/share_name /path/to/mount_point
and everytime i get this message
mount_smbfs: can't get server address: ssyerr = operation timed out
i have also tried this command 
mount -t smbfs //user at server/share_name /path/to/mount_point
and get the same message

can any one give me some ideas to try
thanks alot 
Ben