WiFi not working on Dell Inspiron 6400

[Adam Jocksch]

I've recently gotten a Dell Inspiron 6400 and installed FC5 on it, but I 
can't get WiFi working on the Intel Pro/Wireless 3945ABG card. I've 
tried installing the ipw2200 firmware as has been suggested on the list 
before, but with no success. Also, when I run lspci the following shows 
up instead of my network card:

0b:00.0 Network Controller: Intel Corporation Unknown device 4222 (rev 02)

Any help would be greatly appreciated.