My sarge Debian does not have a z25_... file, not any wifi or ath in any file in the /etc/udev/*.
wlanconfig ath0 create wlandev wifi0 wlanmode sta
wlanconfig: ioctl: Input/output error
ifconfig gives you _only_ ath0? It says nothing about wifi0 or ath1? When I get this message, of late, it means that I have created a VAP
and it doesn't want to bring another up. Try wlanconfig ath create wlandev wifi0. Presumably you have madwifi-ng (now stable, I see) and have not set modules.conf to bring up ath_pci with extra options.... Say: HAVE you set /etc/modules.conf to bring up ath_pci?
-- —A watched bread-crumb never boils. —My hover-craft is full of eels. —[...]and that's the he and the she of it.