Also, bddebian pointed out that gnumach also detects eth1: D-Link in his computer even though it does not exist.
It didn't detect the card, but tried to detect it. If you look carefully in your /dev/klog file you should (probobly) find that GNU Mach found your eepro100 card. Note: Next time please supply the output of /dev/klog too. (End of note) Cheers.
