You don't need to install the ndiswrapper to use your wireless card.
I was able to get it running by following instructions at: http://statgen.ncsu.edu/~jdstarme/fc5_on_t60.txt
Essentially I did the following..
1) Install rpms
yum --enablerepo=ATrpms install ipw3945 ipw3945d ipw3945-ucode ipw3945-kmdl-$(uname -r)
2) Get the wireless kernel modules working...
shell# /sbin/depmod -a (you only have to do this once, right after installing
shell# /sbin/modprobe ipw3945 (load the kernel module)
shell# /sbin/ipw3945d (start the wireless daemon)
and then the wireless networks appear in the NetworkManager applet.
I had a problem, however, with configuring the eth0 and eth1. I solved it by stoppping the NetworkManager* daemons in /etc/init.d
I then configured the network cards using neat and all seemed to work okay
I then created /etc/init.d/wireless after the above webpage
I added the wireless script to start up routine via command:
shell# sbin/chkconfig --add wireless
It now seems to be working pretty well (famous last words...)
I hope this helps.