What model is the wireless nic?
Give this a try. Boot up with a Live CD like Knoppix or Kunbuntu. See if wireless works with this and see if shutdown works from that as well. If it does then you might either try an older version or newer version of Fedora Core. Just trying to either rule out issues on Fedora or all Linux Distros.
Distribution: RHEL 5.1 with Pieces of this and that.
Kernel 18.104.22.168, KDE 3.5.8 and KDE 4.0 beta, Plus Development src.rpm, ATI fglrx64_7_1_0-8.433-1 rpm with 3D and DRI working.
Acer 5100-5840 with webcam, ati, sdcard reader, sound, atheros based wireless, all working. Only thing not working is the memory stick reader.