I've the same problem no wifi and its greyed.
The device is IPHONE 4S, purchased in Feb 2012, upgraded to 5.1.1 in June 2012, and was working properly, till it can't connect to any wifi network. I restarted it then I found this problem.
I tried all kinds of reset (Network Settings, erase all content & settings, reset all settings), then restored to factory settings, and restored to older backup but the problem not solved.
I bought it from KSA (Kingdom of Saudi Arabia), now I'm in Egypt and there are no Apple offices here.
Any suggestion is highly appreciated.