Purchased an iPad mini yesterday (black 64GB wifi). It appears, unlike my iPad 3, that the mini disconnects its wifi connection when put to sleep. Email doesn't come in until I open the Smart Cover and I see the wifi indicator turn back on. This is NOT the behavior of my iPad 3 (or my other two iPads before that). They maintain a persistent wifi connection. Is this normal behavior? I hope not, because it might be a deal-breaker for me.