Why is Wi-Fi not finding preferred networks in MacAir?

I have the same problem with both 11 MBA and 13 MBA, new (2011).

After waking from sleep (usually opening the lid), there is no connection to the network and I get the 'none of your preferred networks can be found' but it then lists the very network that is at the top of my preferred list. Interesting what you say about it maybe coming up with that decision before it's done scanning.

Maybe this is a problem with Lion? What do you have on your old MacBook?

Hi. This has been driving me absolutely crazy. But I've finally found the problem in my case and hopefully it will resolve your problem. I've gone into some detail as not everyone will be familiar their machines.

Steps: Go to Apple Symbol (Top left of screen)/System Preferences/Network/Advanced/Wi-Fi. Even if your Network is listed under "Preferred Networks" if it doesn't have the correct "Security" option, your MacBook Air won't recognize your network. To correct the problem, highlight your network, Click the minus sign, and then click the "+" sign and enter your Network's name and choose the correct "Security" type from the drop drop down menu. If you don't know the type, try the various alternatives. In my case I had Secuity set to "None", but checking on my old Mac Book found that Securtity for my network was WPA2 Personal.

Now when my MBA goes to sleep, it connects automatically to my home network. Relief !!!!

Didn't work for me. I still have the same problem (my security was already correct).

@ souther buyer ,thanks wrked grt

Don't know if that can help anyone, but in my case it only happened with my 802.11g Airport express (Extreme and Time Capsule at home works great).

In my case, I forced the APE in g mode (not b/g), did not help.

The APE was in WPA2 personal only, and at first in network preferences pane my APE security was set to WPA/WPA2 personal. Forcing the preferences to WPA2 personal only, instead of WPA/WPA2 personal did not help.

I then switched the APE to WPA/WPA2 personal, and the same for the preferences, and now it connects every time it gets out of sleep.

So, this helped. But do not know what's wrong with the MacBook Air, as my iPad, iPhone, and my wife MBP never got this issue... very strange.

Thanks for your hint!

I was having the same issue with my macbook pro running Lion. I fixed the issue by opening System Preferences, Network and choosing "Assist Me". I then re-named the "location" and followed the steps to basically set-up my connection from scratch.

This was the only way the problem of "none of my preferred networks being available" even though the network that I was looking for popped up in the list of networks to join, was solved.

I hope this can help.

Steve...your solution worked. THANKS! I've been frustrated by this for a while and could not find anything that worked until now!

Thanks! Solved my problem!

Evan