Whenever i use the internet on my macbook, it frequently stops working. It is still connected to the wi-fi network, but there is no internet (so i cant load webpages, etc.) This has also been going on for another macbook in the household, but the internet on a widows computer is just fine. I have looked from a long time for solutions, i have updated the software, deleted all my saved networks in keychain, i have created a new preferences.plist file as suggested by some forums, but this issue is still going on. Currently, i am using the internet through an ethernet cable and it runs just fine. Can someone help me with this problem? I am running OS X Lion on a mid-2009 macbook pro.