Comment 3 for bug 542001

BTW it doesn't respect HIG 2.2 according to http://library.gnome.org/devel/hig-book/stable/windows-utility.html.en#windows-instant-apply
"Do not make the user press an OK or Apply button to make the changes happen, unless either:
[...]
    * the changes in the window have to be applied simultaneously to prevent the system entering a potentially unstable state. For example, the hostname and proxy fields in a network properties window.
"

A compromised could be to rewrite the content of the entry when the field loses focus.