I have a Mid 2010 MPB, running 10.7.1.
Ever since I upgraded to Lion, I have noticed that wifi connections that require 802.1x authentication are dropping whenever I lock the screen. The connections remain down until I unlock, at which point they quickly start passing traffic again.
This behavior is new as of 10.7.
As I mentioned earlier, this only applies to 802.1x connections. Unencrypted Wifi and non-802.1x connections are not affected. My guess is that the keychain is de-authenticating my 802.1x session when I lock the machine and then re-authenticating when I unlock.
Do you know of any way to prevent this behavior?
Edit: I'm using username/password auth for 802.1x, not certificate auth.