Why is "wpa_supplicant.conf" file invisible? My device LG e510 : Android 2.3 had been rooted and then I changed the privileges to view and see some system files, especially for wpa_supplicant.conf, with RootExplorer app. 

But unlike most people, I can not see the file inside /data/misc/wifi/ directory, it's empty and /system/etc directory has wpa_supplicant.conf header information file.

Lastly I used WifiPassRecovery app, and the app immediatelly retrieved all the saved wifi passwords.

Where did this app retrieve all those informations? and Why cannot I see the file?

Thanks.
On the Galaxy S, the credentials are stored in /data/wifi/bcm_supp.conf (where bcm is short for Broadcom).  Other common locations include /data/wifi/, /data/etc/wifi/ and /data/misc/wifi/ &mdash; check them for relevant config files.