Any GroupManager expert out there? pls help!

I am having trouble with GroupManager.

Using latest spigot:
[12:26:02] [Server thread/INFO]: This server is running CraftBukkit version git-Spigot-1540 (MC: 1.7.9) (Implementing API version 1.7.9-R0.3-SNAPSHOT)

Using latest GroupManager:
[12:26:02] [Server thread/INFO]: [GroupManager] Loading GroupManager v2.1.19 (Phoenix)

This is my groupmanager main config:
http://pastebin.com/GphLiXvU

This is the content of GroupManager/worlds/nosterra/users.yml:
http://pastebin.com/LEtkhdew

This is the content of GroupManager/worlds/nosterra/groups.yml:
http://pastebin.com/tHPZ77hT

For some weird reason the users.yml contains default users I have not even added. And the file is not updated or saved whatever I try.

level-name in server.properties is: Nosterra
but groupmanager creates the folder with a lowercase letter: nosterra
I don't think this could be a problem. But I wanted to mention it.

One more problem. I have deopped my self via server console. I am still listed as OP in "ops.json".
I am in the same group (Default) as all other players BUT still am able to execute admin only commands like stopping the server, reloading groupmanager etc. - WHY?

 

Seek support where you acquired your server mod.