just looked into this a little bit and it looks like the wireless network list does not show up when "/var/run/wpa_supplicant" folder is present.
Deleting the folder and then clicking "refresh" button shows the network list. But then the folder get recreated and the list does not show up again necessitating redeleting the folder.
can anybody confirm this, from the terminal, as root, run the following command and then click "refresh" in the network tool to see if network list will be shown.
rm -rf /var/run/wpa_supplicant