Basically if a Tag is added in front end to a Download then that Download it is not included in the list generated by the Tags menu item until either: the Download is saved in the backend, or another Download has the tag added in the backend.
Tags added to a Download in the Backend appear in the tag list OK.
The tag does appear in the Download view.
If one adds the tag to several Downloads in the front end they all appear in the jD view but not in a tag list. However if one subsequently adds the tag to a Download in the backend then all the 'missing' Downloads are now included in the tag list.
This fault was first reported by wacl3http://www.jdownloads.com/forum/index.php?topic=11912.msg44398#msg44398