I have a brand new MBAir Rev 2 for about 2 weeks now. I have 2 wifi networks in my house (time capsule on 802.11n 5 Ghz & Airport Extreme on 802.11n b/g). Both signals are extremely strong. My mbair used to pick up either signal very very quickly for the first 2 weeks of ownership. Now it scans for about 2-3 mins before it sees either of my networks. Is there anything i can do to return it back to its old state? Thx in advance.