wlan0 not working - F20 arm

[Robert Moskowitz]

I have this old Trendnet usb 802.11bg adapter plugged into my server.  
It is not showing in Network manager (see prior message) so I am trying 
via command lines:

# ifconfig wlan0 up
# iwlist wlan0 scan
wlan0     No scan results

Don't tell me that, my notebook is connected wirelessly and I can see 
b/g support in the APs here.

and

# ifconfig wlan0
wlan0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
         ether 00:14:d1:4c:0f:79  txqueuelen 1000  (Ethernet)
         RX packets 0  bytes 0 (0.0 B)
         RX errors 0  dropped 0  overruns 0  frame 0
         TX packets 0  bytes 0 (0.0 B)
         TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0