A few days ago (september 7) my wireless suddenly stopped working. I am using Fedora Core 11, have an Atheros AR5211 wireless card and have been using the ath5k driver with GNOME NetworkManager. Wireless networks are detected by NM perfectly fine. When I try to connect, the icon spins around those two dots, and one of them becomes green. If the network is wep protected, it asks for the password. After a while, it times out, regardless of the protection.

I don't remember changing pretty much for the last two months, so I'm sort of surprised. I did download and install a kernal, along with an selinux-policy update.

If I run dmesg, relevant looking lines included:
ADDRCONF(NETDEV_UP): wlan0: link is not ready
and a long series of these at the end:
wlan0: direct probe to AP 00:0b:86:4f:8a:20 try 1
wlan0: direct probe to AP 00:0b:86:4f:8a:20 try 1
wlan0: direct probe to AP 00:0b:86:4f:8a:20 try 1
wlan0: direct probe to AP 00:0b:86:4f:8a:20 try 2
wlan0: direct probe to AP 00:0b:86:4f:8a:20 try 3
wlan0: direct probe to AP 00:0b:86:4f:8a:20 timed out
In the middle of one of those was a:
wlan0: privacy configuration mismatch and mixed-cell disabled - disassociate

I had a similar situation and simply turning off and re-setting the router cured it.

Hope it works for you.

Steve (ringo)