Yea you're looking at characters which were created before the first server merge. Initially you could rename your character and it would be fine, but since a second merge happened after that, the ones which were not renamed technically had no name/data to begin with and therefore cannot be logged into until support is contacted and they manually do it for you.

If you didn't explicitly mentioned the #AH (Ahkma) and mention the merge issue, you may want to follow up with it so they know to change it.