Disabled ''Users Logged In Today'' Still Working

I have disabled ''Users Logged In Today'' function at my forum and it is Still working.

My forum is xbrainsforum.createaforum.com

Please Admin! how can I disable it because it slow the Loading of my forum index due to too many users per day i.e. 4000 users per day?

Thanks As you Reply.

Let me look into. Becareful trusting other members as admin.

Especially when the user only has 1 post