There is one bug in:
catalog/includes/column_right.php

at the end just before the closing ?> find:

// Start recently_viewed
if (SHOW_RECENTLY_VIEWED_COLUMN_BOX && basename ($PHP_SELF) != FILENAME_RECENTLY_VIEWED) {
require_once (DIR_WS_BOXES . 'recently_viewed.php');
} // if (SHOW_RECENTLY_VIEWED_COLUMN_BOX
// End recently_viewed

change to:

// Start recently_viewed
if (SHOW_RECENTLY_VIEWED_COLUMN_BOX == 'True' && basename ($PHP_SELF) != FILENAME_RECENTLY_VIEWED) {
require_once (DIR_WS_BOXES . 'recently_viewed.php');
} // if (SHOW_RECENTLY_VIEWED_COLUMN_BOX
// End recently_viewed

The wrong statement let the the recently viewed box show even it was deactivated in admin: show coloumn box = false

Hope this helps

No file included, only text with this instructons. Do the change on your catalog/includes/column_right.php file

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