Cannot login to netatalk server

[alnesbit@optushome.com.au]

I have a very small private LAN with only two machines:

* a Debian box running netatalk 1.5.5 server

* a TiBook running Mac OS X Jaguar

and connected via Ethernet crossover cable.  The network seems to work
fine for other network functions (for example, ping and ssh), but I am
unable to login to the Debian box from the TiBook via Appletalk.

When I do Go -> Connect to server from the Finder on the TiBook, the
Debian box shows up in the "Connect to server" window.  I then select it
and enter my username and password to the Debian box.  After quite a
while, authentication fails and I get an error message

"Login failed. Unknown user, incorrect password or log on disabled. Please
retype the name and password or contact the server's administrator."

I've followed the error message, but I am still stuck.  I can't see how
log on would be refused -- I have no firewall, no entries in
hosts.{allow,deny}, and a vanilla netatalk installation from Debian
packages.

I've been bashing my head against this problem on and off for about a week
now and am at my wit's end, so any advice would be wonderful.  Thankyou!

Andrew.