AFAI remember in my setup I used the following line after the AmiTCP Assign in User-Startup:
C:SetPrism2Defaults SSID
KEY
Then everything worked like a charm 
Edit: The Genesis config was made easily by the Wizard plus some alterations to the prefs.
I found it pretty easy compared to manual AmiTCP installation with WiFi over my A600. Both work just fine though
