eth2: unknown interface: No such device

Hello all
I'testing the at76c503 driver on a WUSB11 v.2.6 connected (via USB) on a PPC 
based board. The setup is the following: 

the file /etc/network/interfaces contain the following lines to set the 
wireless network interface: 

auto eth2
iface eth2 inet static
    address 10.0.0.2
    network 10.0.0.0
    netmask 255.255.255.0
    broadcast 10.0.0.255
    gateway 10.0.0.1
    wireless_mode ad_hoc
    wireless_essid lynksys
    wireless_channel 6 

The /etc/modules.conf has been modified to properly handle the driver
	
alias eth2 at76c503
options at76c503 debug=0x100003 

When I load the module I receive the following message: 

usb.c: registered new driver usbdevfs
registered new driver c60c042c probe=c60b69d4
register: usb_driver_list next=c60c0438 prev=c60c0438
usb.c: registered new driver hub
registered new driver c60c03f8 probe=c60b4c9c
register: usb_driver_list next=c60c0438 prev=c60c0404
at76c503.c: Generic Atmel at76c503/at76c505 routines v0.11beta1
SIOCSIFADDR: No such device
eth2: unknown interface: No such device
SIOCSIFNETMASK: No such device
SIOCSIFBRDADDR: No such device
eth2: unknown interface: No such device
eth2: unknown interface: No such device 

If I try to configure eth2 by hand with iwconfig
I receive the following message
eth2:   no such device
The eth2 interface is unknown. Probably I haven't set up correctly the eth2 
and this is a "absolute beginner" question and this isn't the most right 
place where to ask for help about this item, but I hope that anyone could 
help me. Any suggest will be appreciated.
Thank you for your attention. 

Fabio Antonini
Kasko Networks S.r.l.
Via Patini 46 67100 L'Aquila - Italy
Ph/Fax +3986265562
e-mail: [email protected]