I'm having a problem where one of my menus keeps creating the following URL:

index.php?option=com_content&id=82&view=category&Itemid=667

This is giving me a page in "Category" view, but that menu item is linked to a single article (which has its own SEF url), which is strange. If I delete the SEF url it gets recreated automatically. If I disable the menu item and delete the SEF url, it stays deleted, so I know that it is this one menu that is causing this URL.

Any suggestions on why this is happening?