I can't connect my MacBook air to the internet on a Sprint hotspot. It was working fine before, and it works perfectly everywhere else. Also, every other computer (including a pc I'm using now) can connect to the internet with this hotspot, but mine. The airport recognizes the network, connects to it, but when I try to browse something it shows an exclamation mark, the alert says "No internet connection..." while it has full signal! I don't know what to do. I've tried several times to use the Network Diagnostics, I've deleted the network from my preferred networks... don't know what else to do. Please, can someone help me?