Well switching AppleTalk on and off won't make much difference seeing as the Pismo is talking to the G3 via IP and not AppleTalk to access the internet, all you need to make sure is that you're connecting via ethernet in TCP/IP control panel which you've done. That's basically told the Pismo to talk IP down the the ethernet cable to the G3. Check the configuration and setup settings in the TCP/IP control panel and make sure the Pismo can see the IP address of the G3. If it can't see its IP address, it won't be able to talk to it.