Works fine for me, and have confirmation from others, although it does not work as as before (pre ics, the optios would for example say 5ghz only, and now they are 5ghz preffered).
Possibly the app you used to edit with screws with permissions. Also if your rom uses others.xml, edit that, if the main is feature.xml for your rom options, then of course, edit that.
Permissions should reflect permissions of other files in that csc folder.
Sent from my SGH-I337M
"Glory is fleeting, but obscurity is forever!!!"