I know it`s an old topic but i have a problem related.
After a while after rebooting my phone (i9505) e.g. after 30 minutes when my wifi is on and connected to any wifi and i run some app that uses localization service (gps/wifi localization) wifi disconnects. Using apps that don`t try to locate my phone (Opera, Google play etc.) no probs, but using Google Maps, Sygic or any other app that tries to locate my phone keep disconecting wifi.
I determined that it happens only when i have "use wireless networks" under location settings set to ON. When i shut it down there`s no problem with wifi.
I`d like to use that feature but i makes me going crazy everytime disconnecting wifi.