@brianc69:
The question is how to fix it? I tried the above but the backup gets restored automatically. What am I missing? Why does it keep coming back?
Editing the entry out of the config is the easiest way. If you get the message that a config is being restored it means you removed too much or the wrong chunk, leaving it with invalid XML. Be sure to only remove the one menu tag and its contents and no lines above/below it.
Downloading a config backup, editing it, and then restoring it is the safest way, rather than editing live.