I have two Macs that I use in my apartment on the same WiFi network. The network is made with my Apple Airport Extreme router. The problem is, on the iMac (2009), internet works perfectly. I checked on speedtest.net, it is just as it should be! On the Macbook Pro (2006), it is horrible. It may take up to half an hour to load a 4 minute YouTube video, a minute to load a page, etc. The WiFi connection on both is 4/4. I have done a software update for both of them recently. Please help, Thanks.