When at home, I'm always connected to wifi. When I take the phone out of sleep mode, it shows it was using 3G but immediately switches back to wifi. Sometimes I queue downloads and walk away; I want to stay connected to wifi during sleep mode. I don't see anything in the settings menu that refers to this. Help! Also, not sure if it's related, but I first noticed this quirk after I installed then uninstalled Power Manager (free version).