Okay, so here is a really odd one for you guys... Here is my situation, I have an MacBook with 802.11n and a Windows laptop also with an N card. I've got an AirPort Extreme and two AirPort Express's for speakers in my living room and bedroom and they also extend my wireless signal. I also live in apartment building and have a couple of neighbors who I know well enough to trust with giving free WiFi too, but I don't know them well enough to let them on my network. Plus I don't want to be giving my WiFi password out to people, nor keep it open. So Guest Network to the rescue! With one issue. Since I have the Dual Band AE I have created a 2.4GHz and 5GHz network. Also my guest network. Everything on my network works great: TiVo, Blu-Ray Player, PC Laptop, and cell phones. When I connect to my network with the white MacBook it connects to the AE just fine(get full signal) but does not connect to the internet. Meanwhile I'm streaming netflix and my PC laptop is working fine. If I switch to the guest network I can connect to the internet just fine. I try to go to the 2.4GHz network, nothing. I've tried taking off all of the AirPort Express's and still the same issue. If I get rid of the guest network everything works great. Anyone ever seen this before or have any other things that I can try? Let me know!