TC55 Keep Wi-Fi on during sleep

I've tried setting Keep Wi-Fi on during sleep to 'Always', but find that as soon as the device sleeps, that it disconnects from the network. (I can no longer ping the device from my PC)

 

This means that push notifications to our Rhodes app stops working. (Using RhoConnect and the rhoconnect-push-service.apk).

 

Is it possible to get the Wi-Fi to stay on?

 

Mike