On the Powerbook, in Control Panels | Network, I now see a new icon, "Ethertalk". Unfortunately, when I try to select it as my AppleTalk Connection, the Powerbook gives this error message:
"You cannot choose a zone at this time because no internet router is available."

What should I do next?

Click to expand...

It looks like you are on a simple non-routed AppleTalk network (eg all the network addresses are 65xxx., hence would not have multiple zones. Hence no zones to choose from.

Does the icon for Ethertalk stay highlighted within the Network window? Can you close it with the Ethertalk icon highlighted? Does it then say "Switching AppleTalk connections..."?