Question : Problem: Macbook Air problems with Wireless Access Point Network of Aironet and Linksys

I maintain a wireless network with 3 wireless access points.   Currently we have two Cisco Aironet 1100s one on Channel 11, the other on Channel 1.  We also have one Linksys WAP54G on Chennel 6.  We are running 40 bit WEP for security.  All  access points share a common SSID.   I can move throughout the building with Windows PCs and with our MacBooks without a problem.   The signal strength remains strong throughout.
The problem is with a new MacBook Air that my client just purchased.   She says that the wireless worked when she got it but it stopped working right a few days ago.   My tests show that it locks in on one WAP when you start it up and it works fine if you don't move.   It can be the Linksys or an Aironet, usully the LInksys.   As you move through the building it doesn't let go of the original WAP, it holds on to the connection until it loses signal.  It seems to only work with two WAPs at one time.   At times I can start it up inches from a WAP but it never sees it.   Take it to where it finds one of the other WAPs and it's fine.
I'm trying to determine if this is a MacBook Air hardware problem with this unit, a MacBook Air firmware problem or a problem between the Air and Cisco Aironet WAPs.   It seems to have an affinity for the Linksys.
Has anyone else had similar experiences with the MacBook Air or Aironets?

Answer : Problem: Macbook Air problems with Wireless Access Point Network of Aironet and Linksys

I was able to migrate the WEP security to WPA-2 Personal.    Once done, the MacBook Air conencted without a problem.    It looks like the "Air" has a problem with WEP security.   This was confirmed by an Apple Technician.