I updated my iPhone 4 last night to iOS 4.1 and today I am seeing an extreme drop in performance of network applications (over att network, not wifi). At work, I usually get between 3 and 4 bars of service before the upgrade and today I have the same, and do not have issues loading web pages, refreshing twitter or facebook, etc. But today I have had to restart my device about 4 times to even be able to load any simple web page (even google), or refresh any app that uses connection. Is anyone else having these issues since upgrading to 4.1?