Teamspeak 3 Server admin bug or so ??

Hi there,

We, as a clan, have a clan TS3 server (rented from a company). I'm an admin there (with SA rights, I have no server login or something).
I have a friend, Danny (not his real name). One day I gave Danny SA rights. I had an argument with him, so I took his SA rights away (that was few hours later).
Now I can't take his SA rights away. I take it away, somehow he gives himself SA rights back. I don't know HOW he does that.

We have 4 Server groups.
1. Server admin
2. Guest
3. Clan Member
4. VIP

Does anyone know how he does that? I want to know so I can take his SA rights away.

Thanks a lot.

Teamspeak 3 Server admin bug or so ??