Hi folks, First few days of having the phone, everything was great. Now, when I lock the phone the WIFI basically disables itself. I can tell because when I push the home button, the icon at the top re-appears. This is pretty annoying because I use iMessage a fair bit and 3G signal seems to absolutely wreck battery life when I have a poor signal (so I keep it disabled) Effectively, when the phone is locked things such as push mail and notifications have been deemed useless. I thought persistent WIFI was something iOS did these days?