[ydl-gen] PowerBook G4 wireless problems on YDL 6.0

[furio ercolessi]

I installed YDL 6.0 on a PowerBook G4 (1.5 GHz 15"). All went well,
except that it does not recognize the Airport wireless.  I found
http://www.terrasoftsolutions.com/support/solutions/ydl_5.x/airport-extreme.shtml
, assumed that the same applies to YDL 6 and proceeded to follow these
instructions.  lspci says  "Broadcom Corporation BCM4306 802.11b/g Wireless 
LAN Controller (rev 03)" as expected, and I installed the .fw files in 
/lib/firmware after extracting them from the driver in OSX 10.3
(no 10.4 at hand, and the procedure does not work with 10.5).
The device is seen by the kernel (from /var/log/messages):
Apr  7 11:48:51 systemname kernel: bcm43xx driver
Apr  7 11:48:51 systemname kernel: b43-phy0: Broadcom 4306 WLAN found

Then I configured the interface as eth1 with system-config-network
(which seemed to know about the device in the Hardware subpanel). 
I configured it as an Ethernet device, because if I try to add a 
Wireless device I do not see the BCM4306 in the device list.
So I assumed that the OS sees this chip as an Ethernet.
However, this is suspect (where am I supposed to configure the wifi
network infos then?).

Now the problem: the interface won't come up.  When I click on Activate I get:

Cannot activate device eth1!
bcm43xx device eth1 does not seem to be present, delaying initialization.

and of course eth1 does not show up using ifconfig.

I suspect that something may be wrong in /etc/modprobe.conf.  
In an attempt to made things working, I inserted manually

alias eth1 bcm43xx

in replacement of some other unrelated driver - probably put there
by the script - that did not work either.  However I do not know
exactly what I am doing here, and my line could also be wrong.
I would really appreciate suggestions from people with the Airport
working.

Thanks in advance

furio