I just had my MBP replaced by Apple yesterday with the new late 2011 15" model. Everything was working fine at first, then when I tried logging into my friend's network, anytime I try to connect to any WiFi network, I get the "!" over the WiFi bars on the status bars and it says "Alert: No Internet Connection." I tried deleting all saved networks, rebooting, etc. I'll try my Windows partition in a sec and post results... Anybody have any suggestions? Thanks. UPDATE: Same thing happens in my Windows partition. It actually does connect to the router, just not the internet. Now, here's where it gets weird... My IPHONE somehow, completely coincidentally, cannot connect to my room's Wifi either. I haven't tested my phone on other networks yet. Ethernet on my MBP and 3G on my iPhone work fine though. I tried resetting my iPhone's network settings, but only get the spinning wheel when I try to connect to my network.