Then if I try and ping a computer on the same subnet (no gateway
   inbetween) I get:
   ed2: device timeout

   What could be wrong now?

This would indicate that the driver is never getting a transmit
completed interrupt.

It sounds to me like you have shared memory and/or interrupt
conflicts, but you haven't really supplied enough information about
your setup.

What, exactly, is in the machine, and how, exactly, is everything
configured?