The SANAII drivers (FastEthernet.device and MediatorNET.device) should be placed into the DEVS:Networks drawer (create it if you dont already have this drawer)
When entering the SANA II driver name into your TCP/IP stack, please note that it is case sensitive e.g. DEVS:Networks/FastEthernet.device and not fastethernet.device
Also ensure you have the ENVARC: settings to specify the speed the network card should go Half or Full Duplex or Auto Negotiation.
We stock a suitable Mediator card here with EasyNet software included:
http://amigakit.leamancomputing.com/...products_id=63