Every so often I attempt to share files from my imac to iBook via Airport cards. I am running OS 10.3.9.

The airport always connects, but the problem I have is with the file sharing. When I am trying to select the server (in this case the other computer) to log on to, it doesn't always work, and when it does eventually provide the window allowing me to select between registered user and guest, I sometimes can't log in with either, even though I have not changed any of my passwords.

In this case the window that pops up is:

ˆLogin failed: Unknown user, incorrect password, or log on is disabled. Please retype the name and password or contact the servers administratorˆ

I don't have firewalls on, and as far as I can tell all the appropriate channels are switched on.

Does anyone have a foolproof way of filesharing between two computers reliably or can anyone shed any light on what I'm doing wrong?