Webalizer Stats - 404

Hi there,
I am really going nuts with this seemingly simple task of viewing Webalizer stats. Our webserver is on Wheezy, ISPConfig runs on version 3.0.5.4p9 - everything works as expected. Stats are being generated, but so far, we have always used PIWIK or Google Analytics. Now a client wants to take a quick peek at collected data, so I added a password in the Statistics tab in ISPConfig - htpasswd worked, but after successfull login I got a 404 - even though all files were there in /stats/ (index, usage and PNG files) .
Permissions are 644, owned by webuser/group - it seemed something else was prohibiting the index.html
I have searched the forum, none of the solutions seem to apply / work. There is a Joomla HTACCESS file in root, but turning oit off shows no effect. I even tried turning off mod_security to no avail. In logs there is only a PHP date() warning (after I tried turning on AWStats).

After uploading a simply test.html file and adding parts from the stats index, I found that the word "webalizer" seems to trigger the 404 -
simply REMOVING any instance of the word "webalizer" from the stats html files will show all stats! Very strange.

Any ideas anyone?

Thanks,
Richard

 

Yes, there is a Joomla 3.5 .htaccess - but the issue persists even after deleting the file