03eb:7614 Atmel Corp.: can't load firmware

I am trying to use a "Inventel wireless magic",
ID are:

03eb:7614

I can read ID 03eb:7614 Atmel Corp. from lsusb.

I've tried to modify the c source with this ID without result:

sample from dmesg:
unregister_netdevice: device eth%d/c7390800 never was registered
at76c503.c: at76c503_new_device returned NULL
at76c503.c: load_ext_fw_block failed: -32, i = 0
at76c503.c: getting firmware failed with -32, or version is 0
at76c503.c: this probably means that the ext. fw was not loaded correctly
unregister_netdevice: device eth%d/c7390800 never was registered
at76c503.c: at76c503_new_device returned NULL
usb.c: USB device 14 (vend/prod 0x3eb/0x7614) is not claimed by any 
active driver.

I'm not sure I'm taking the good way, I'd like to know if I could find 
the firmware somewhere and make it load ?

Wich kind of info do you need in order to determine what it is ?

Regards

JoDaY