Hi guys, Let's see if you can figure this one out. I have a MacBook pro and an iPhone 4. I work at my office using both (mostly the former, but you know what I mean). Ever since upgrading to Lion, although I don't know if this is related, I haven't been able to connect to the office's wifi twice. That means, I've gone to the office, and I couldn't connect, so I had to go back home and work from there. A few days later, I went back to the office, forgot the name of the network, deleted the entry off the keychain just in case, and it worked ok again. And then again, today, it happened again. Interestingly enough, my iPhone wasn't able to connect either. It does connect to the router, but I have no internet connection. It says that another device is using my IP (I'm using DHCP, but I tried DHCP with manual IP) chose a few that weren't being used, and still no luck. I tried forgetting the network, deleting the keychain, rebooting the router, my system, turning off my iPhone's wifi in case that's the "other device"... nothing. Any ideas?