iPad 2 Cannot connect to Internet 3G after iOS 4.3

I had updated my iPad 2 WiFi + 3G to iOS 4.3. When I took it off airplane mode, turned off WiFi and connect to 3G, it shows a full 3G signal but won't connect. Then I turned on WiFi and connect to WiFi, Internet worked fine.That must be an iOS 4.3 bug. I just turn on wifi, then turn it off then open safari and 3G now connects.