Starting this morning the WiFi connection on my iPhone 4 will periodically drop out. But what's even more strange is that the WiFi indicator that displays the signal strength completely disappears - only to re-appear in a few minutes. This happens when the iPhone is literally right next to the router, so it's not an issue of signal strength. Two nights ago I forgot to plug my phone in and it completely ran out of juice. Yesterday, when I powered the phone back up, it said "waiting for activation" even though my phone has long been activated. Then none of my third party apps would open. I had to delete them and re-install them from the iTunes store. I'm not sure if this WiFi problem was triggered by the power shut down too, but I've never experienced it before and it seemed to start shortly after that happened. I've tried hard reset and resetting all settings, but that didn't help. Any ideas?