Comment 7 for bug 1198983

Thanks Dan, I just encountered this myself. Your solutions both sound sane to me.

As a stop-gap, if anyone needs to get things working quickly in their environment, you can clear the user agent string via staff client custom.js entry (web/xul/server/skin/custom.js)

---
try {
    var prefs = Components.classes['@mozilla.org/preferences-service;1']
        .getService(Components.interfaces['nsIPrefBranch']);
    prefs.clearUserPref('general.useragent.override')
} catch(E) {
    dump('Error clearing "general.useragent.override" in custom.js for '
        + location.href + '\n' + E + '\n');
}
----

We can toss the same code (more or less) right into the staff client proper somewhere, though where it should live, I'm not sure....