I get this error message in Statistics.

The URL is not valid.

Error #404: Not found (http://www.WEBSITE.com.au/Scripts/lm_fo ... ml&lang=us)

The delivery 9 table shows entries as normal. But then the message will pop up.

What's wrong?

If you try to open that URL with your browser you get a 'Not Found' error from your server. That means http://www.web.com.au/Scripts/lm_folder/lm/lm.php doesn't exist on your server.

Actually, it is working.
If I open the URL on the browser, it's OK.

But every now and again I get that message.
Sometimes when I select a Delivery #.
Sometimes while it's loading/refreshing it's window.
Then I refresh or update and the window reloads as normal.

If the error message does not come out, you wouldn't suspect anything wrong.

Is it something to do with network speed? bandwidth? server busy? I certainly NOT the URL.

Any ideas?

It is something on your server for sure. Some kind of http server failure or DNS lookup failure.