Copying plist settings

Hi,

Having set a USB audio device to default in Preferences>audio I was hoping that I could simply copy the modified plist to /Library/Preferences/Audio on several other macs so my settings would be applied for anybody that logs in. I copy the said file to a remote mac using ARD. I logged in and realised my custom settings had not taken effect. The odd thing is that when I look at the file using plist editor, the settings are how they should be, but it is not so when I look in preferences>audio

I have restarted the mac but to no avail. Not sure why or how it still holds the old settings when the new file has been modified.

This is a bit confusion to explain so hopefully somebody understands me :O)