Did you install it using ndiswrapper? Sometimes a kernel upgrade using yum or something else cause it to break and you have to reinstall ndiswrapper all over again.
I installed F12 around the time it was released and it picked up my wireless card and worked like a charm.....Suddenly last week everything stopped working and I receive what appears to be a driver error when wlan0 tries to load.
Error for wireless request "Set Mode" (8B06) :
SET failed on device wlan0 ; Invalid argument.
Error for wireless request "Set Encode" (8B2A) :
invalid argument "if902c7885".
Broadcom Corporation BCM4318 [AirForce One 54g] 802.11g Wireless LAN Controller [14e4:4318] (rev 02)
Subsystem: Dell Wireless 1370 WLAN Mini-PCI Card [1028:0005]
A quick google cam of with plenty of issues related to older versions of Fedora but nothing in F12..Any ideas?