I had the same problem and found no solution.
"Admin" ist always "admin" in the forum, also with assigned special rank.
When you assign a special rank to a moderator, he has it in forums, where someone else is the moderator, but in that forum, where he is the mod, his rank changes to "moderator".
I donīt believe, thereīs a simple solution for that.
I so the following now. I Use the username "Admin" only for the administration of the backend and take a normal user for myself, when I am on the frontend.
I know no other way...
