I have been having intermittent wifi dropping ever since I installed lion. I've tried about every single solution beyond reinstalling and nothing seems to stick. I've tried adding a new network location, changed the DNS to 126.96.36.199, done manual TCP/IP, all kinds of things. Sometime it will go for hours without dropping then it will start, and drop every 5 minutes several times and then it will be stable again for a few more hours. I noticed it seems to drop mostly when time machine is backing up and sometime when waking from sleep. Does reinstalling lion make a change in the stability of the wifi connection? Once connected my speed is super fast if I could only get it to connect and keep it connected. It's driving me crazy! Please help with any solutions that have worked.